Field Manual Headquarters

No. 5-102 Department of the Army

Washington, DC, 14 March 1985

FM 5-102

COUNTERMOBILITY DISTRIBUTION RESTRICTION. This publication contains technical or operational information that is for official Government use only. Distribution is limited to US Government agencies. Requests from outside the US Government for release of this publication under the Freedom of Information Act or the Foreign Military Sales Program must be made to HQ, TRADOC, Fort Monroe, VA 23651-5000.

Table of Contents

Introduction

Chapter 1 -COUNTERMOBILITY ON THE BATTLEFIELD

The Battlefield

Threat Engineers

Countermobility Requirements

SummaryChapter 2 - COUNTERMOBILITYFUNDAMENTALS

Types of Obstacles

Existing Obstacles

Reinforcing Obstacles

Principles of Obstacle Employment

Summary

Chapter 3 - COMMAND AND CONTROL

Levels of Responsibility

Reserve Obstacles

Summary

Chapter 4 - OBSTACLE PLANS

Planning Considerations

The Planning Process

Offensive Planning Considerations

Defensive Planning Considerations

Retrograde Planning Considerations

Summary

Chapter 5 - MINE WARFARE

Classification

Minefield Employment

Minefield Employment Authority

Reporting, Recording, and Marking

Summary

Chapter 6 - OBSTACLES OTHER THAN MINEFIELDS

Bridge Demolitions

Non-nuclear Craters

Antitank Ditches

Expedient Obstacles

Preconstructed Obstacles

Atomic Demolition Munitions

SummaryChapter 7 - DENIAL OPERATIONS

Authority and Responsibility

Denial Targets

Denial Methods

Denial Planning

Summary

Chapter 8 - CONSIDERATIONS FOR SPECIAL OPERATIONS

Supporting Light Forces

Special Terrain Environments

Combined Operations

Contingency Operations

Summary

Appendix A - OPERATIONS ORDERS

Appendix B - STRONGPOINTS

Appendix C - OBSTACLE NUMBERING SYSTEM

Appendix D - STANDARD OBSTACLES

GLOSSARY

REFERENCES

AUTHORIZATION LETTER

COUNTERMOBILITY

The foundation for engineer doctrine in the AirLand Battle is built with combinedmobility, countermobility, and survivability efforts. This manual provides the basicframework of fielded and developmental countermobility methods, planning, andexecution. Its purpose is to integrate countermobility into the overall AirLand Battlestructure.Countermobility support is divided into mine warfare and obstacle development, eachwith an ultimate goal of delaying, stopping, or channelizing the enemy. Mine warfareexpands to include mine categories, methods and systems of delivery, employment,reporting, recording, and marking. Obstacle development demonstrates innovativetechniques and conventional improvements in planning and emplacing obstacles otherthan minefields.Countermobility effort is not secluded; rather, it balances with the other majorbattlefield missions of mobility and survivability, as well as general engineering andtopography. The overall teamwork and planning process are both evident and essentialwith each facet of countermobility.

STANAG IMPLEMENTATION

The provisions of this publication are the subject of the following internationalStandardization Agreements: STANAG 2017, Orders to the Demolition GuardCommanders and Demolition Firing Party Commander (Non-Nuclear); STANAG 2036,Land Minefield Laying, Recording, Reporting and Marking Procedures; STANAG 2096,Reporting Engineer Information in the Field; STANAG 2123, Non-Nuclear DemolitionTarget Folder; and STANAG 2889, Marking of Hazardous Areas and Routes ThroughThem.

USER INFORMATION

Users of this manual are encouraged to submit recommended changes to improve themanual. Comments should identify the area in which the change is recommended.Reasons should be provided for each comment to allow complete evaluation. Commentsshould be prepared using DA Form 2028 (Recommended Changes to Publications andBlank Forms) and forwarded directly to the Commandant, US Army Engineer School,Fort Belvoir, VA 22060-5291.

When used in this publication, "he," "him," and "his" are used to represent the enemy.

Chapter 1

COUNTERMOBILITY ON THE BATTLEFIELD

This chapter focuses upon a modern battlefield against an enemy using Soviet styletactics and organizations. It discusses the modern battlefield, emphasizes threatoperational concepts, particularly threat engineers and their capability to providecountermine and counterobstacle support to the offense, and covers the importance offriendly countermobility activities to deny the threat freedom of movement. THE BATTLEFIELD THREAT ENGINEERS COUNTERMOBILITY REQUIREMENTS SUMMARY

THE BATTLEFIELD

The most dangerous threat to United States' (US) national interests will most likelyinvolve highly trained enemy forces using Soviet style tactics, organizations, andequipment. The actual battle will be intense, fast, and deadly. United States forces musttherefore be prepared and trained to fight on a future battlefield where-- • Highly mobile forces will use combat systems delivering firepower of unprecedented volume, speed, accuracy, range, and lethality. • Airspace will be crowded with aerial combat, surveillance, transport, reconnaissance, and target acquisition systems. • Communications systems will be the target of indirect fire and sophisticated electronic warfare operations, making command and control difficult to achieve and maintain. • Scatterable mine systems will severely affect ground mobility due to rapid and remote delivery means. • Employment of nuclear, biological, and chemical (NBC) weapons will create anew experience and add new dimensions to the environmental conditions.Ultimate success on the battlefield will depend on mobility and countermobility efforts,not only near the forward line of own troops (FLOT), but also in rear areas. Successfulcommanders will need to concentrate forces at the decisive time and place, makemaximum use of unit versatility, exercise movement and maneuver, impede the opposingforce's movement and maneuver, and preclude enemy reinforcement of committed unitsand their resupply.

THREAT ENGINEERS

Engineers play a vital role in the success of threat army combined arms operations. In thethreat view, the greater the increase in mobile warfare, the greater the need for passableterrain. Therefore, stated in simple terms, the mission of the threat combat engineers is tokeep the offense moving. Threat engineers are organized, equipped, and trained toaccomplish this mission under fire and in all environments including NBC.

ORGANIZATION

All tank and motorized rifle units down through the regimental level have organicengineer elements. In combat, these elements form special engineer combat groups--either under control of parent command or attached to subordinate commands--toperform direct support missions. Engineer elements are also combined with other branchelements in operational groupings to perform specific tasks. At higher echelons (Front orCombined Arms Army), considerable engineer reserves are maintained either forconcentrated use as needed, or for attachment to subordinate formations. This reserveallows rapid switching of engineer effort from one area to another, affording maximumtactical and operational flexibility. Furthermore, it is not unusual for the senior formationcommander to strip a unit of its engineer element when that element is required for aconcentrated effort elsewhere on the battlefield.Doctrine emphasizes that commanders at all levels must strive for maximum flexibility inusing engineer assets, inasmuch as engineer tasks are not isolated but are part of theoverall tactical plan.Combat engineer units at any level are of two general types: engineer special/technicalunits or general purpose engineer units.Special/technical units perform the following tasks: • Engineer reconnaissance. • Road and route preparation. • Field fortification construction. • Bridge construction. • Camouflage. • Assault river crossing. • Obstacle construction and/or removal. • Minefield breaching and clearing. • Water supply.General purpose engineers may perform any or several of the above tasks, but usually toa lesser degree than their special/technical counterparts. In either case, the threatenvisions that most if not all of these tasks are conducted under fire or well in advance ofmain assault elements.Technical repair of pipelines and topographic surveying are not the responsibility ofthreat engineer units. In addition, many simple and general engineer tasks are not carriedout by engineer soldiers, but by soldiers of other combat arms. For example, all threatcombat soldiers are expected to be proficient at mine clearance. The operation of tank-mounted mine plows and rollers is a responsibility of armored forces, although engineeradvice is available in deciding whether to employ such devices.The organization of threat engineer units is the result of careful study and is designed toaccomplish specific objectives. These objectives are: • Conducting engineer tasks necessary to support the tactical employment of other combat arms, especially the movement of tank and motorized rifle elements. • Attaching additional engineer assets to subordinate elements and maintaining a significant engineer reserve. • Dovetailing and expanding engineer tasks in the offense by follow-on engineer elements of increased capabilities. • Providing cohesion to the defense and security in the offense by employing mines, obstacles, field fortifications, and antitank defenses.The structure of engineer units is constant at the regimental and divisional levels, but notat higher levels of command. The engineer units assigned to a Front or Combined ArmsArmy will vary with the level of importance of the major command in the overalloperational or strategic plan. Generally, a Front engineer reserve is likely to be twice aslarge as that of a Combined Arms Army.

PRINCIPLES OF THREAT ENGINEER EMPLOYMENT

Threat military principles are observed in order of precedence. To a certain extent, threatmilitary principles appear as rephrasing of Western principles of war. However, applyingthese principles is peculiar to threat military theory, and threat units are configured andequipped to attain them. These eight military principles, in order of priority, are:1 Mobility and high rates of combat operations.2 Concentration of main efforts and creation of superiority in forces and means over theenemy at the decisive time and place.3 Surprise and security.4 Combat activeness (constant combat and pressure).5 Preservation of the combat effectiveness of friendly forces.6 Conformity to the goal.7 Coordination.8 Action upon the enemy to the entire depths of his employment and deep into his reararea.These principles are basic to a threat officer's approach to any combat problem, and willhave a profound effect on any decision made. For example, achievement of high speed inthe execution of combat missions is the first principle, and will therefore take precedenceover the need to avoid casualties and preserve the combat effectiveness of friendly troops.In other words, saving time is more important than saving lives, since fewer lives wouldbe lost if the threat commander is allowed to exercise battlefield initiative and dictate theterms of combat. While adhering to these principles, the role of combat engineers is toassist other elements of combat arms to follow them more closely, thereby attaininggreater combat effectiveness.The threat has certain principles peculiar to combat engineers. These principles arebinding upon the engineer commander and state that combat engineer operations must-- • Correspond to the impending battle concept and support the commander's plan. • Be completed in time to allow the completion of tactical activities necessary in implementing the plan. • Be concealed to deprive the enemy of intelligence indicators. • Contribute directly to the effect of the main attack in the offense or the main sector in the defense. • Be capable of rapid maneuver to adapt to changing battlefield situations. • Deceive the enemy regarding the direction or location of the main effort.

THREAT ENGINEER SUPPORT OF THE OFFENSE

In the offense, the chief function of engineers is to assist in maintaining high rates ofmovement, which is the premier tactical principle of threat military doctrine. Emphasis isplaced on clearing and maintaining routes for the advance of combined arms units, toinclude breaching or removing mines and obstacles, crossing water obstacles, andassisting in flank protection or protection against counterattack. Engineer reconnaissance,independently or in collaboration with other reconnaissance means, plays a significantrole in facilitating movement. Camouflage and protection during halts or temporaryassumption of the defense are also basic engineer functions.Secondary attention is given to supporting logistic operations in rear areas. The practicaleffect of these engineer requirements is to create certain key functions which must besatisfied by engineer troops. These functions include: • Engineer reconnaissance. • Movement support. • Mine and countermine warfare. • Wet and dry gap crossings.

Engineer reconnaissance

The goal of engineer reconnaissance is to provide a comprehensive report on the

passability of march routes. Engineer reconnaissance is conducted by engineer elementsattached to combined arms or reconnaissance units, or by engineer officers acting as partof the commander's reconnaissance party which checks the validity of plans made fromintelligence without actual prior inspection of the terrain. Engineer elements performingthis reconnaissance must determine-- • The degree of passability of the entire route. • The location and nature of obstacles to be overcome and the engineer assets required to overcome them. • The condition of all crossing sites, wet or dry. • The location and quantity of material which can be used to improve the march route. • The nature of the terrain and location of areas with natural concealment.In the conduct of engineer reconnaissance, the most commonly employed formation isthe Soviet engineer reconnaissance patrol, Inzhenerny Razvedyvatel'ny Dozer (IRD). TheIRD may vary in strength from a squad to a platoon. Commanded by an officer or seniornoncommissioned officer (NCO), it is equipped with the necessary equipment foraccomplishing its task. The IRD will almost always be vehicle-mounted, utilizing thereconnaissance version of the BRDM or BTR60. The commander is issued maps andaerial photographs of the march route and provided with the column compositionindicating the number and types of vehicles the route must accommodate.

Significance to Friendly Forces

The appearance of engineer reconnaissance elements serves as an important intelligence

indicator of impending offensive action. In addition, since engineer reconnaissance isnormally conducted one to one-and-a-half days in advance of the main force's movement,it provides highly valuable information regarding the timing of threat activity. Sincethreat offensive tactics are predicated upon high rates of movement and engineers areparamount in implementing this movement, friendly counterreconnaissance actiondirected against IRDs will deprive the threat commander of engineer intelligence vital toexecuting the tactical plan. Finally, the documents carried by the IRD commanderprovide portions of the threat commander's actual tactical plan.When in close proximity to enemy forces occupying prepared defensive positions, threatengineer reconnaissance will be conducted in a different manner than when it supports anapproach march. In such an instance, existing intelligence concerning roads, topography,defenses, and the like, will be initially supplemented by aerial photography and aerialvisual reconnaissance. Engineers will be attached to many combined arms reconnaissanceelements. The IRDs will be employed to penetrate defenses to reconnoiter either aspecific avenue of approach or particular defensive fortifications and obstacles.Additionally, reconnaissance may be conducted by establishing covert engineerobservation posts close to, or actually within, the defensive sector.One engineer observation post (OP) is normally established per 2 kilometers of front inorder to observe the entire enemy FLOT and ascertain the engineer action and equipmentnecessary to properly support the attack. As the attack progresses, these OPs continue toobserve the effectiveness of the engineer assault and make recommendations concerningalteration of the operation plan or commitment of the engineer reserve. The purpose ofengineer reconnaissance is to develop intelligence supporting the employment of firstechelon assault elements. The value of denying engineer information through aggressivecounterreconnaissance cannot be overemphasized. Since assault engineer tasks are aprerequisite to the execution of the threat commander's tactical plan, any friendly actionwhich interferes with these tasks will concurrently degrade the execution of the plan.

Movement support

The threat army believes that, without adequate engineer preparation, the approach marchis sometimes not possible at all. Therefore, the results of engineer reconnaissance servetwo purposes:1 Selecting column routes which require the least engineer preparation.2 Planning the employment of engineer assets for any route clearing needed.Principles of movementConsidering the results of engineer reconnaissance and the tactical requirements of theoperation plan, the commander selects the unit's approach route. The Chief of EngineerServices then drafts the engineer plan for movement support. This plan is based upon twoprinciples:1 Engineer soldiers must be equitably dispersed throughout the march column to insureproper engineer support to the entire formation.2 Engineer soldiers must work as far in advance as possible.Threat doctrinal texts state that movement support elements should ideally operate one-half day in advance of the main force. The manual task of route preparation usually fallsto a temporary organization called a movement support detachment, OtriadObespecheniya Dvizheniya (OOD). Several OODs can be formed from the engineerbattalion of the tank and motorized rifle division, while additional OOD assets exist inthe engineer companies of the tank and motorized rifle regiments.Responsibilities of the OODsSpecific responsibilities include the following: • Clearing and leveling areas of movement. • Building approaches and exits at streams, ravines, or other obstacles. • Constructing bypasses. • Breaching and clearing mines. • Marking routes.The organization of the OOD may vary depending on the scale of work undertaken andthe assets available. In general, the faster the desired rate of advance, the stronger theOOD. In most if not all cases, the OOD will be reinforced with tank and motorized rifleelements to assist engineers in those tasks conducted under fire. Typical variations in thestructure of OODs are shown in the following illustration. The groups are organizedhaving the following missions: • Reconnaissance and Barricade Destruction Group: Reconnoiters march route, clears obstructions, and selects column route. • Road and Bridge Group: Prepares route and provides crossings. • Route Marking Group: Marks route and provides security and traffic controlMoving into position directly behind the division's advanced guard, or sometime behindthe advanced guard's point security patrol, the OOD normally moves about 1 to 2 hoursin advance of the head of the march formation. A typical sequence of activities for anOOD would consist of: • The reconnaissance and barricade destruction group reconnoiters enemy minefield and obstacles protecting a river crossing. Obstacles are cleared by engineers using explosives, while plow and roller-equipped tanks clear lanes. through the minefield. Using information previously obtained by an IRD, additional reconnaissance of the river banks is conducted to determine the exact extent of preparation necessary for bridging. Enemy troops in the area are engaged by tank and motorized rifle elements. • Road and bridge groups improve initial lanes through minefield, prepare banks for bridging equipment, and emplace bridges. • As preceding groups continue movement, the route marking group emplaces required route and bridge markers, establishes traffic control points, and regulates traffic flow until relieved by military police traffic units. • The threat uses smoke and supporting indirect fire as necessary to assist the OOD in accomplishing required tasks.Threat doctrine for route preparation stipulates that, as an average, a divisional engineerbattalion should be able to prepare up to 100 kilometers of route per day in open countrywhere roads or tracks have not been subjected to specific enemy action to block ordestroy them. If the route has been specifically interdicted by the enemy, then only 20 to40 kilometers per day can be achieved, less if the engineer tasks must be conducted underfire, In such cases, it is common for threat engineers to construct a rough track parallel tothe planned route, if possible, in order to maintain the tempo of the advance.

Significance to Friendly Forces

Threat offensive operations are predicated upon high speed execution and the sequencedarrival and departure of combined arms teams at specific locations at designated times.Thus, dependent upon an exceptionally high degree of coordination, the threatcommander relies to a critical extent upon the movement support activities of hisengineer troops. Action which denies the accomplishment of engineer route preparationactivities may create a potentially disastrous situation for the threat commander. Thedelay of an advancing column by an unexpected obstacle not only disrupts coordinationand slows the tempo of battle, but also causes succeeding units to combine with those infront, creating a highly rewarding target for friendly fires.

Mine and countermine warfare

In the threat view, the most important features of mines are speed and ease ofemplacement on the battlefield. Emplacing a mine belt is considered much more effectiveand efficient against infantry and tanks than trenches, wire, or other fortifications. Minesare a much quicker means of erecting a defense. Consequently, they are widely used evenin offensive operations. In supporting the offense, engineers employ extensive minefieldin several situations such as-- • When temporarily assuming the defense. • When protecting against counterattack. • When providing flank protection.In any future war, the threat believes there will be no distinct front line nor a clearlydefined forward edge of the battle area (FEBA) or FLOT. Rather, there will be a series ofoffensive and counteroffensive axes in the form of spurs and salients. Given the fluidityof combat under such conditions, a mine obstacle offers far greater flexibility inemployment than antitank ditches, tetrahedrons, and other such relatively static obstacles.Minefield will be the most common means of protecting vulnerable aspects of offensivedeployment, and mined areas may be expected to be far greater than those encountered inWorld War II. Although all threat troops are trained in the fundamentals of mine warfare,combat engineers are specially trained to perform this function. The primary combatengineer element performing mine warfare support for the offense is a temporaryorganization called a mobile obstacle detachment, Podvizhnoy Otriad Zagrazhdeniya(POZ), which is formed from elements of regimental and divisional combat engineers.In the offense, POZs are positioned on the flanks of the march column, and usually areclosely associated with the antitank reserve. Each POZ will be equipped with up to threePMR-3/60 minelaying trailers with towed mine-carrying vehicles, or the newer GMZtracked armored mine-laying vehicle which is rapidly replacing the older PMR-3/60. Incertain instances, the Mi-8/HIP helicopter with removable mine racks and chutedispensers may be used to emplace mines from an altitude of about 5 meters. A divisionalPOZ equipped with the GMZ tractor is capable of emplacing a 1,000-meter minefieldcontaining 750 to 1,000 mines at 4-or 5.5-meter intervals within 30 minutes on suitableground.Temporary assumption of the defensiveIf the attack fails, engineers must be prepared to conduct rapid fortification and obstacleactivity in support of the hasty defense. In this role, POZs will perform as they do inoffensive combat and emplace mines in accordance with the overall defensive plan.Protection against counterattackIn planning the offensive employment of the command, the threat commander constantlyevaluates the battlefield for suitable enemy counterattack areas. Areas identified asfavorable are usually those which would detract from the maneuver of the combined armsteams, and be considered vital for mine employment in order to deny the enemycommander tactical initiative.Flank protectionEngaging in a battle of dispersion and maneuver necessarily creates extensive exposedflanks. In threat theory, preventing enemy exploitation of such a condition relies, on twoactions: rapid execution of combat tasks before the enemy can react, and protection offlanks by extensive minefield. During the march to contact and during the engagementitself, POZs actively emplace mines on the flanks of maneuvering units to preclude beingattacked by mobile forces of the enemy.In the late 1960s and early 1970s, the tendency for a POZ to create an obstacle byalternating minefield with other antitank obstacles along a 6- to 7-kilometer front is nowconsidered ineffective, as is the practice of laying long strip minefield without coveringthem by antitank fire. Current threat teaching stresses the need for anititank guns toengage tanks as soon as they encounter the minefield. Thus, a short, deep mine and gunobstacle belt is preferred to a long, thin one, making choice of position critical.Because of the possible need to recover minefield as the advance progresses,antipersonnel mines are rarely included in an antitank minefield laid in support ofoffensive operations. Minefields left behind are clearly marked and recorded, and theirlocations are reported to the Chief of Engineer Services.

Significance to Friendly Forces

In the offense, the commander employs mines in areas evaluated as offering the enemy asignificant advantage to interfere with the tactical plan. Thus, the detection of minelayingactivity offers the friendly force an indication of the manner in which the threat commandwill be employed, and highlights those areas deemed critical to success.The threat, in planning for the widespread employment of mines, fully expects anyenemy to engage in extensive mine warfare. Consequently, countermine warfare is anextremely important task entrusted to combat engineers. Breaching lanes through enemyminefield is critical to the goal of keeping the attack moving. Equally important is thedesirability of conducting mine breaching operations covertly, whenever possible, topreserve surprise. When attacking from the march, the location of enemy minefield is theresponsibility of engineer reconnaissance patrols (IRDs). The IRD is equipped withseveral types of mine detectors, the most common being the DIM metallic mine detectormounted on the UAZ 69, 1/4-ton, 4 x 4 Light Utility Vehicle. The DIM is synchronizedwith the vehicle's ignition system and, upon detecting a metallic mine, cuts out theelectrical system and kills the engine. The IRD reconnoiters the limits of the minefieldand marks it for the following movement support detachment (OOD).In breaching the required number of lanes through the minefield, the OOD will employseveral types of mine breaching equipment. The normal threat method of breachingminefield during an assault or rapid advance is to employ mine plows fitted to the leadtanks. Although engineers will reconnoiter the minefield, the initial breaching is notprimarily an engineer task. The KMT-4 and KMT-6 plows are normally employed on thescale of one per platoon of three to four tanks. Engineers assist in fitting these and plow-roller combinations (KMT-5s) commonly used for minefield reconnaissance. The threatestimates clearing speeds of about 6 kilometers per hour (kph) for plow-fitted tanks, andabout 10 kph for roller-fitted tanks. Combat vehicles follow these plow-equipped tanks inthe breaching of a minefield. The threat employs a mine-clearing device mounted on theBTR-50 PK Armored Personnel Carrier (APC) (two to each divisional engineerbattalion). This device fires and then detonates an explosive hose (line charge) across theminefield. It clears a lane about 180 meters long by 6 to 8 meters wide. This equipment isparticularly useful during an assault river crossing when there are minefield on the farbank and amphibious vehicles may have to initially operate in the bridgehead withouttank support.Another mine-clearing device is the explosive line charge. It consists of three separatelinear charges, a nose section, and a detonator box. Each linear charge may be assembledto any desired length by connecting 2-meter sections together with threaded collars. Thelight, sheet metal, 5-centimeter-diameter, tubular sections are filled with casttrinitrotoluene (TNT) explosive at 9 kilograms per linear meter. This device is versatile inthat it may be used as a single, double, or triple charge. The forward end section is fittedwith a roller to facilitate insertion of the charge into a minefield. The device is assembledin a rear area, towed by tank to the minefield's edge, pushed into the minefield, and fired.The triple line charge will clear a 6-meter-wide path along the entire length of the charge.A squad can assemble a 500-meter-long triple charge in 1 to 1.5 hours.Bangalore torpedoes are also used. Sections, 2 meters in length, carrying 6 kilograms ofexplosive, are connected by collars. The clearance depth of a path 1 to 2 meters wide islimited only by the manageable weight that can be manually pushed into the minefield.The number of lanes to be cleared depends on the terrain and the number of columns inthe assault echelon. For a leading battalion in the assault on a main axis, six to eight lanesmay be required, one for each assaulting platoon. In secondary sectors, as few as twolanes may be sufficient. However, an average of four to six lanes can be expected with atleast two developed into permanent lanes, 6 to 8 meters wide, for passage of artillery andlogistic vehicles. Engineers mark minefield lanes and provide traffic control through theminefield. The routes leading from a start line to each lane are marked with red triangularmetal flags and black-and-white tapes. Illuminating markers may be used at night. Routesthrough friendly minefield are marked by signs of various shapes placed not less than 20meters apart on both sides of the route. If possible, they are positioned so as not to bevisible from enemy positions.In attacking from line of march, manual mine breaching is carried out only under certainconditions: • As nuisance minefield along or on routes, especially around craters and demolitions, to allow the route clearing unit to work freely. • On approaches to water obstacles and water mines. • To maintain surprise, especially at night or when the threat wishes to make a gap in their own minefields. • When other mine breaching equipment is committed.When conducting assault breaching operations against a defended enemy minefield, theusual practice is to attack with combined arms teams led by combat engineers andsupported by artillery and tactical aviation. Such a formation is necessary if the combatengineers are not to suffer crippling losses to defensive fires. Artillery, in particular, playsa major role in suppressing defensive fires and allowing the execution of engineer tasks.If artillery support is not available or is too short in duration, the first wave of the attackis led by plow-and roller-equipped tanks, while combat engineers closely follow to widenlanes. Here again, the use of plow-and roller-equipped tanks is not an engineerresponsibility, but an engineer function carried out by tank soldiers. Another means oflane improvement entails mine clearing tanks dragging a variable length of explosive linecharge. The charge is detonated to clear mines not uncovered by the plow or roller. Ourminefield should be deep enough to preclude the threat from breaching the entire depthwith one line charge. The threat breaching capability with one line charge is curently inthe 50-meter range. A threat squad can assemble a 500-meter-long triple charge in 1 to1.5 hours by coupling the 50-meter sections together. Planners should check the currentthreat capability for breaching before determining what size minefield is most effective.As with much of threat engineer activity, threat mine and countermine operations provideboth intelligence and tactical values to friendly forces. Minefield breaching activity isindicative of impending threat offensive action, and the identification of such activity willgreatly assist in determining times and locations of attack. However, it must be kept inmind that threat doctrine calls for the conduct of bogus mine clearing activity as part ofcover and deception plans. Tactically, the denial of threat countermine actions serves todeprive the threat commander of the tactical initiative which his entire operation plan isbased. River crossings

Threat military doctrine dictates that, whenever possible, water obstacles along a broadfront are crossed at multiple points without pause in the march or the advance. This tacticis designed to rapidly overwhelm enemy defenses and maintain the tempo of the attack.In the threat view, a delay at a major water obstacle can jeopardize the success of anentire offensive operation in conventional combat, and is certain to destroy large forcesmassed for the crossing during a nuclear war. Consequently, the threat recognizes twodistinct forms of river crossing, hasty and deliberate.Hasty crossingThe hasty crossing incorporates the features of rapid movement previously mentioned.The attacking force crosses the water obstacle in stride, does not stop to consolidatebridgeheads, and continues the advance without pausing. This is the preferred form ofriver crossing.Deliberate crossingThe deliberate crossing is conducted when an attempted hasty crossing has failed, orwhen hostilities are being initiated against a well-prepared enemy occupying a river linedefense. It is characterized by more detailed planning, extensive buildup and preparation,and a greater degree of centralization than the hasty crossing.The role of combat engineers in both types of crossing is critical. While all arms are fullytrained in their individual roles in river crossing operations, engineer functions providethe margin of success. It is not the purpose of this section to examine river crossingoperations in their entirety, but to define the role of engineers within the overall effort.For a complete account of the conduct of river crossing operations by all arms, seeDefense Intelligence Agency (DIA) Publication DDI-1150-13-77.Engineer support to assault river crossings by threat forces occurs in the following areas: • Engineer reconnaissance of water crossings. • Route and site preparation. • Crossing preparation and execution. • Site protection. • Support to units within the bridgehead.Engineer reconnaissance of water crossingsIn the threat view, the key to a successful river crossing is thorough reconnaissance todetermine both the tactical situation and the technical characteristics of the river and itsbanks. As a general principle, reconnaissance will be carried out across a wide front toavoid focusing enemy attention on one area. Additionally, this activity identifies thenumerous crossing sites needed to support the crossing of widely dispersed units.Engineer reconnaissance personnel will attempt to ascertain the following information ateach site: • River width, depth, and current. • Entry and exit gradients. • River bottom composition. • Bank composition and height. • Approach and exit routes. • Critical terrain features dominating both banks. • Possible fording, ferrying, bridging, and snorkeling sites. • Information on enemy defenses.In obtaining this information, engineers may, as in other offensive operations, accompanycombined arms reconnaissance teams; or, engineer patrols (IRDs) may operateindependently. An IRD will usually operate from the BRDM engineer reconnaissancevehicle and will be equipped with a variety of reconnaissance equipment. In someinstances, engineers are clandestinely dropped by parachute directly on the waterobstacle.A typical reconnaissance mission for a squad-size IRD might require the reconnaissanceof two sites in a 500- to 600-meter sector, a task usually accomplished in 4 hours. Scuba-equipped engineers check for water mines and test riverbed conditions. Other members ofthe IRD select and mark concealed approach routes; obtain hydrographic data by usingdepth finders and water current meters; determine river bank conditions and the presenceof existing or military obstacles; identify enemy defenses and conduct bogusreconnaissance activity in other areas to avoid disclosing the main crossing sector.

Significance to Friendly Forces

Engineer reconnaissance performed in support of water crossings has both intelligence

and tactical value to the friendly force. Conducting engineer reconnaissance will assist inidentifying planned crossing sites for combined arms teams and the times of attack. Suchinformation is of extreme importance in planning the friendly tactical response.Counterreconnaissance, which prevents the accomplishment of engineer reconnaissancemissions, deprives the threat commander of information vital to the successful executionof attack.Route and site preparationRoute preparation of approaches to crossing points will follow the same procedures as inthe approach march. Movement support detachments (OODs) will accompany thevanguard elements of advance forces to provide trafficable conditions for the types andnumbers of vehicles in the column. A division will usually cross a river on a wide front ata minimum of four points (sometimes up to eight) simultaneously, seeking to findsuitable areas for each type of crossing means. This requires the engineer staff tocarefully plan and allocate engineer assets.The preparation of proper entry and exit bank gradients is crucial and depends upon theresults of the reconnaissance effort. Earthmoving equipment and explosives are used inpreparing bridge approaches and entry and exit points at ford, ferry, and swim sites.Rapid execution of these tasks is essential, since the actual crossing units follow closelybehind and depend on suitably prepared crossing points before commencing operations. Significance to Friendly Forces

Site preparation is a critical phase of a threat river crossing operation. Interference withsite preparation activity translates directly to interference with the sequence and timing ofthe engineer effort, which the entire crossing is dependent upon. If the site preparationeffort can be denied, the following crossing units will either be unable to perform theirfunction or forced to halt. The tempo of the attack will be disrupted, and the consequentbunching of units will create lucrative targets. For these reasons, site preparationrepresents the most vulnerable aspect of a threat river crossing.Crossing preparation and executionFollowing the initial site preparation, and immediately prior to actual crossing, finalpreparatory activities are executed. Previously located water mines are destroyed byscuba-equipped engineers using explosives. Where necessary, metal matting is emplacedat soft bottom fords. Engineers in amphibious APCs accompany initial assault waves andassist in reducing defenses on the far bank.During the actual crossing, the ferry operation and bridge emplacement are solelyengineer functions. Additionally, engineers are responsible for traffic control anddirection at all crossing sites. In the latter role, engineers insure that the crossing isconducted at a high rate of speed, a requirement considered to be extremely important.Threat doctrine establishes the desired crossing time for the division combat elements as3 hours during daylight and 6 to 8 hours at night.

Significance to Friendly Forces

The primary role of engineers during this phase is providing the physical means by whichthe bulk of the division crosses. This phase of engineer operations also marks the arrivalof major combined arms teams, and is usually supported by artillery fires. In most cases,it will be conducted under the protection of the air defense umbrella.Site protectionCommencing with initial site preparation and continuing through the conduct of thecrossing, engineer elements are responsible for protecting the site, equipment, andcombined arms teams from floating mines and enemy raids. Scuba divers and powerboats will constantly patrol both upstream and downstream approaches to the crossingsite, and outposts will be established along likely land approaches.

Significance to Friendly Forces

When planning raids against threat gap-crossing sites, the presence and locations of thesesecurity forces already established by prior reconnaissance should be considered.Support to units within the bridgeheadAs the threat force establishes itself on the opposite bank, elements of the engineerreserve accompany combined arms teams in performing engineer tasks necessary to keepthe advance moving. In this role, engineers function in the same manner as whensupporting the attack from the line of march or when in contact with the enemy. Thecrossing site will gradually become the responsibility of lines of communication troops,and the combat engineers will rejoin the division and be prepared to support the nextcrossing operation.

Significance to Friendly Forces

As with other threat engineer activity, the shift of engineer emphasis accompanies a shiftin tactical emphasis. Friendly action which destroys or damages bridging and ferryingequipment during this phase will reduce the threat ability to conduct subsequent rivercrossings until equipment is replaced.

COUNTERMOBILITY REQUIREMENTS

In order for the threat to attain its primary military principle, Mobility and High Ratesof Combat Operations, it is imperative that they preserve their ability to move andmaneuver on the battlefield. Threat forces are designed, organized, trained, and equippedto accomplish this principle above all others.Friendly US countermobility tasks must therefore be designed and executed to slow themovement rate specified by the threat. The use of countermobility by friendly forces mustbe integrated into the concept of operations not only to impede threat mobility, but toincrease the kill probability of friendly firepower. Obstacles must be sited to reinforce theterrain and maximize the effective firepower from friendly battle positions.Countermobility operations will be used along the FLOT as well as deep into the threatrear area. The use of scatterable minefield gives friendly forces a capability to deny threatmobility anywhere on the battlefield. The use of scatterable minefield should be carefullyplanned and executed so that friendly mobility during future operations is not impeded.Countermobility execution is primarily the responsibility of combat engineers. Theengineer and the tactical commander must decide early in the planning process how tobest position obstacles to increase the effectiveness of friendly fire and maneuver.Tactical commanders must establish countermobility priorities early in the planningprocess. Early planning will enable maximum effort to be devoted to thosecountermobility tasks deemed most critical.Countermobility activities are essential in order to defeat the first principle of the threatarmy; that is, delay, channel, or stop the offensive movement. An analysis of recent warsshows that effective and well-planned integration of countermobility activities andfirepower can enable an outnumbered force to win. SUMMARY

In supporting offensive operations, the role of threat combat engineers is to keep theoffense moving. The extreme importance of this effort to the overall conduct of theoffense cannot be overemphasized. As has been noted, threat offensive combat ispredicated upon mobility, high rates of advance, surprise, and secrecy, and the closecoordination of all arms. While first appearing to be highly fluid in nature, closeinspection reveals threat style offensives to be predicated upon the carefully synchronizedand sequenced interplay of rapidly moving units.The mission of engineers is to create conditions of movement which will allow thisnoticeably complicated activity to occur unhindered, and enable the threat commander toenjoy total tactical initiative while denying it to the enemy.Combat engineers are thus one of the key elements of the offense. Any friendly activitywhich prevents combat engineers from accomplishing their mission will seriouslyinterfere with the actions of combined arms teams and create exploitable tacticalsituations for the friendly commander.Chapter 2

COUNTERMOBILITY FUNDAMENTALS

This chapter provides a standard classification and a detailed discussion of existing andreinforcing obstacles. The principles of terrain evaluation and the employment of all ofobstacles to reinforce existing terrain are also presented. TYPES OF OBSTACLES EXISTING OBSTACLES REINFORCING OBSTACLES PRINCIPLES OF OBSTACLE EMPLOYMENT SUMMARY

TYPES OF OBSTACLES

An obstacle is defined as any obstruction that stops, delays, or restricts movement or

maneuver. Obstacles can exist naturally such as a river or a cliff, or can be man-madesuch as a minefield or tank ditch.Obstacles are grouped into two general categories, existing and reinforcing, as shown.Existing obstacles are already present on the battlefield and not placed there throughmilitary effort. They may be natural such as lakes or mountains, or they can be culturalsuch as towns or railroad embankments. Reinforcing obstacles are placed on thebattlefield through military effort and are designed to strengthen the existing terrain toslow, stop, or canalize the enemy. Reinforcing obstacles are limited only by imagination,time, manpower, or logistic constraints. They include blowing a road crater, constructinga log crib, or installing a minefield. Scatterable mines are reinforcing obstacles emplacedby various delivery systems such as artillery or aircraft.

EXISTING OBSTACLES

The terrain, as it exists, can be a significant asset to the commander who is best able toanalyze and use it advantageously. Terrain is not just the field where the battle is fought--it is very much a part of the battle itself. The commander at any level who makes theterrain work in a positive manner against the opponent will most likely win.There are many things a commander needs to know about the terrain on which US andenemy forces must move, maneuver, and fight. Some of the more obvious items are: • Roads and bridges. • Built-up areas. • Soil and trafficability. • Slope. • Rivers and streams. • Visibility, climate, weather, and their effects.The commander's course of action will largely depend on the characteristics of the terrainand intended use of it. The commander's action includes movement, maneuver, andweapons siting to destroy the enemy. All ground movement, friendly or enemy, will bedictated by existing obstacles.A good analysis of the terrain in the areas of influence and interest should answer thefollowing questions: • Where are the mobility corridors and avenues of approach? (Where will the enemy come from? Where can I go?) • How large are the mobility corridors and avenues of approach? (What size enemy or friendly force will they support?) • What is the trafficability of the avenues of approach? (How fast can the enemy or I travel and with what type vehicles?) • Where is the key terrain? (What terrain will provide a significant advantage to the one who controls it?) • What are the fields of fire? (With what weapons and at what ranges can I engage the enemy? Or be engaged?) • Where are the choke points or extensive obstacle areas? (Where are possible locations to place reinforcing obstacles?)These questions are not inclusive, but if answered and analyzed, they will providesignificant information on how to prepare the battlefield and allocate combat power.Determining existing obstacle locations is a key element in terrain analysis. The mostcritical questions are how and where do we get information concerning terrain andexisting obstacles. The best source is an on-the-ground reconnaissance accomplished bythe units who will fight the battle. However, this is not always possible due to lack ofresources or enemy control of the areas about which we need information. Corps anddivision terrain teams organic to the Theater Army Topographic Battalion collect,analyze, and provide important topographic, hydrologic, and climatic data. Terrainanalysts assess observation and fields of fire, cover and concealment, obstacles tomovement, key terrain, and avenues of approach. Input to the force engineer and G-3 isespecially important for obstacle planning. Engineer terrain analysts work as a team withintelligence analysts to collect raw terrain information and convert it into processedintelligence. Topographic units provide a variety of products including cross-countrymovement maps, overprinted maps, and various scale tactical maps. Topographic supportis invaluable in making a thorough terrain analysis.Analysis of terrain and existing obstacles should focus on the mobility of tanks. Tacticsof enemy combined arms forces are designed around the mobility of tanks. The tank isthe primary vehicle we want to restrict, delay, stop, and kill. This antitank orientation ofterrain analysis and obstacle development narrows our focus and makes the task moresimple. By focusing on the tank, the terrain analysis team can assist the commander inidentifying those existing obstacles that restrict, channelize, delay, or stop the mobility oftanks.Systematic terrain analysis using all assets available reveals the existing obstacle valueof the terrain. Conditions which should be considered when analyzing terrain includedrainage features, slope and relief, vegetation, cultural features, and climate. The obstaclevalue of each condition is evaluated individually in conjunction with trafficability. Then,their combined effects become the obstacle value of the terrain.

DRAINAGE FEATURES

Drainage or surface water features include rivers, streams, canals, lakes, ponds, marshes,swamps, and bogs. Such features are obstacles whenever the water becomes deep orturbulent enough to threaten the safety of soldiers and the operation of vehicles. Drainagefeatures are also obstacles when swamps, marshes, bogs, and the like make soilconditions impossible for cross-country movement.

Large rivers

Large, unfoldable rivers are formidable obstacles because they must be crossed bytactical bridging, swimming, ferrying, or special deep water fording. Ease of crossingthese rivers is determined by the width, depth, velocity, turbulence, bank and bottomconditions, rapid tactical bridging available, and existing bridges.

Small rivers, streams, and canals

Minor fordable rivers, streams, and canals are much more numerous than major riversand their tactical value as obstacles should not be overlooked. These features are variablein effectiveness as obstacles. Careful planning is required to integrate them into theobstacle system. Watercourses frequently constitute elongated obstacles in terrain whichmay otherwise be excellent for movement. Drainage also influences the orientation of theroad net and direction of movement in an area. The destruction of a few selected bridgescan force cross-country movement or long detours. During floods, minor rivers andstreams can become major obstacles. They can cause conditions which extend theobstacle effect for a considerable period by damaging temporary and expedient bridges,and by deepening the original channel of the river or stream, thus making access or egressdifficult or impossible. Weather effects

Although streams are normally small and slow during periods of low precipitation, andlarge and rapid during periods of high precipitation, the relationship is not always thissimple. Melting snow, for example, may cause high water downstream even in regionswhere rainfall is low. Continuous below-freezing weather can reduce stream flow eventhough precipitation may be high.In winter, ice may be strong enough to support vehicles; then, instead of being obstacles,water bodies may become the preferred avenues for movement. Lightly loaded 2 ½-tontrucks can move on ice 0.3-meter (10 inches) thick. Movement on ice is risky, however,because of weaknesses caused by water flowing from springs and other areas of swiftlymoving water.In arid regions, dry stream channels maybe preferred avenues for movement duringperiods of little or no flow. However, there may be quicksand or other soft places wherevehicles bog down. Also, there is the danger of flash floods.

Fording

Fordability of a stream expresses how easily it may be crossed without the means ofbridging or ferrying. Fordability depends on characteristics of both the vehicle and thestream. The significant characteristics of streams are: • Width of channel. • Depth and velocity of water. • Nature of bottom. • Height, slope, and strength of banks.

FORDING IS POSSIBLE IF DEPTH AND BOTTOM PERMIT ACCESS AND EGRESS.

These characteristics may vary independently so that fording of even the smallest streamrequires selecting a site where favorable conditions coincide. A stream is a minorhindrance when a ford is available and usable with little or no improvement. A stream isa major hindrance if a suitable ford is lacking, or if fording requires considerablepreparation of approaches, reinforcement of bottoms, or the use of special equipment onvehicles.

TANKS CAN "SELF-BRIDGE" UP TO 3M.

A tank can bridge stream channels less than 3 meters wide; however, wheeled vehicles donot have this capability. Once the self-bridging capability of tracked vehicles is exceeded,streams can be crossed only by bridging, ferrying, or fording. Although the width of astream is significant to bridging, it is relatively insignificant to ferrying (provided it iswide enough) and fording. However, the wider the stream, the greater the hazardinvolved. For fording, the permissible maximum depth of water for most tanks is between0.9 to 1.5 meters (3 to 5 feet); and for trucks, about 0.9 meter (3 feet). Vehicles can beequipped with deep water fording devices that will enable them to cross water bodies asdeep as 5 to 6 meters (17 to 20 feet). Often, a ford may be negotiated with minordifficulty by the first few vehicles, but the ones remaining will be unable to cross becausebottom conditions or approaches have deteriorated with use.

TANKS CAN FORD

WATER UP TO 1.5M DEEP AND 1.5M/SECOND VELOCITY.

Stream velocities should be less than 1.5 meters (5 feet) per second for reasonably safefording. The bottom of stream channels must be firm enough to support vehicles.Bottoms made up of fine-grained material can prevent fording even though the water maybe only a few inches deep. Suitable bottoms are restricted to those that are sandy,gravelly, or rocky; but even sandy bottoms may give way under the weight of vehicles, orboulders may prevent vehicular movement. The banks also are important. Hard, verticalbanks will be obstacles to tanks, if bank height exceeds 1.5 meters (4 feet), and to trucks,if bank height exceeds 0.3 meter (1 foot). Greater heights can be tolerated if the vehiclescan get adequate traction or if assistance such as winching is used. The type of thematerial composing the banks may be significant. Banks made up of fine-grained soilsmay fail under repeated traffic. Sandy and gravelly materials usually provide adequatestrength and durability. GROUND RECON IS ALWAYS BEST.

Adequate information (river studies, special maps) is commonly available on large

streams, but generally not for the small streams. Ground reconnaissance is always thebest source of information; for many areas, it is the only reliable source. If on-site reconis not possible, then topographic and geographic maps, reports, and aerial photographsare often the only sources of information available. Occasionally, useful data can befound in publications on geology, agriculture, soils, and forestry.

Lakes, ponds, swamps, marshes, and bogs

Large lakes make excellent obstacles. They are usually unfordable, unable to be bridged,and must be bypassed. Smaller lakes and ponds in themselves are not difficult to bypass;however, when connected by streams, they are easily integrated as part of an obstaclesystem. Because lakes can be crossed by amphibious vehicles or boats, beach andunderwater obstacles should be used to discourage enemy ferrying efforts. When lakesare frozen, they may lose their value as obstacles. Swamps, marshes, and bogs severelyrestrict mobility and force the canalization of vehicular movement onto causeways,greatly increasing vulnerability to air attack, artillery, or direct fire weapons. Historically,swamps have been avoided by attacking armies. Swamps and marshes over 1 meter deepmaybe more effective obstacles than rivers, since causeways are usually more difficult toconstruct than bridges.

Soils

Soil trafficability, especially when considered in conjunction with climatic conditions, is

a very important factor in evaluating cross-country movement. Obtaining the necessaryinformation, however, is difficult and time-consuming; and, properly evaluatingtrafficability strength of soils is a complicated process.

SOIL TRAFFICABILITY IS DIFFICULT TO EVALUATE, DETERIORATES WITH USE, AND VARIES WITH MOISTURE.

Engineer soils analysis personnel and qualified photo-interpreters are capable of

estimating soil. strengths usually required by higher headquarters for planning purposes.The load-bearing capacity of fine-grained soils such as clay, loam, and silt is significantlyaffected by soil moisture due to the effects of drainage on the water table or weather.Artificially produced high-water tables have made obstacles of meadows or paddy fieldswhich covered large areas. Further, the long-term use of manure for fertilizer addsorganic material that reduces soil's trafficability when wet. The combination of soft orslippery soils, and even slight slopes, will stop many vehicles. Tanks have extremely lowground pressures (8 to 12 pounds per square inch (psi); 0.56 to 0.85 kilograms per squarecentimeter (kg/cm2)). They have less difficulty with most soils than other vehicles unlessunusual wetness or repeated traffic have reduced normal trafficability.

BEARING STRENGTH LESS THAN 8 PSI STOPS TANKS.

Snow

Snow creates a special cross-country movement problem related to soils. Though it is

seldom deep enough to be a serious obstacle to tracked vehicles, snow in the spring orfall may occur over saturated, untrafficable ground. It is considerably more of ahindrance and hazard to wheeled vehicles, as most will become immobilized when thedepth of the snow reaches one third of the tire's diameter. Snow reduces slope climbingability, maximum payload capacity, and maneuverability and speed of all vehicleoperations.

SLOPE AND RELIEF

Slope is the inclined surface of a hill, mountain, ridge, or any other part of the earth's landsurface. It is the inclination not only of major surface relief features (hills andmountains), but also of minor relief features such as ditches, small gullies, mounds, lowescarpments, small pinnacles, and sinkholes which generally do not appear ontopographic maps. Although some of the minor relief features might be considered aroughness factor rather than slope, they are included in the general slope factor becausetheir obstacle value is due to the steepness of their slopes, banks, or faces. Short, verticalslopes or "steps" higher than 0.3 meter (1 foot), will slow wheeled vehicles, and 1.5meters (4 feet) will stop tanks.

STEPS OF 1.5M HIGH WILL STOP TANKS.

In mountainous areas, the steep slopes commonly make cross-country vehicular

movement either difficult or impossible. Movement will be channelized by existingterrain. The amount of slope is usually expressed as a percentage, which is the number ofmeters of elevation difference per 100 meters of horizontal distance. Most militaryvehicles are able to climb slopes of 60 percent (about 30/35 degrees) under optimumconditions. This limit, however, is too great to negotiate in military operations. Inevaluating terrain for cross-country movement, 45 percent (about 27 degrees) iscommonly used as the reasonable upper limit for tanks, and 30 percent (about 17 degrees)for trucks. Wet weather, trees, unfavorable soil conditions, snow, boulders, and theemployment of reinforcing obstacles may make gentle slopes impassable. SLOPE OF 45% (27°) IS PRACTICAL UPPER LIMIT FOR TANKS.

The most reliable information on slopes, particularly short, steep ones, is obtained by on-site reconnaissance. At best, however, slope can be determined on only a small portion ofthe area by this procedure. Topographic maps are useful but some features may not beshown; for example, small gullies. Terrain teams are the best overall source of up-to-dateinformation to determine slope and other terrain information if an on-site reconnaissanceis not possible.

VEGETATION

Vegetation includes not only natural, "wild" vegetation, but also cultivated forests andcrops. Forest vegetation is the primary concern in cross-country movement. Trees are theprincipal obstacles to movement. Although high grass and brush can obstruct vision, theyare of relatively little significance in most cases. Nearly all forests, however, have aslowing effect on movement.The problem is to determine whether a particular forest will slow movement slightly,drastically, or stop it altogether. Temperate zone forests tend to canalize movement sincethe roads, trails, and firebreaks through them provide the only means for rapid movement.Reinforcing obstacles readily strengthen the defensive value of woods, and are placedboth outside and inside the wooded area to delay the advance of the enemy and betterutilize supporting fires.

TREES 20 TO 25CM IN DIAMETER, SPACED NOT MORE THAN 5M APART, ARE OBSTACLES TO TANKS.

Tree size and density, soil condition, slope, and depth of forests contribute to theirobstacle value. Forests with trees 20 to 25 centimeters (8 to 10 inches) in diameter aretank obstacles, and 5-centimeter (2-inch) stands will stop most wheeled vehicles. Fullydependable criteria pertaining to the size of trees, and the significance of species and rootsystems, have not been determined. Medium tanks, for example, have pushed over singletrees as much as 30 centimeters (12 inches) in diameter. Overturning trees within standscan also create complications; for example, if several trees are pushed over, some willinterlock with other trees to form a better obstacle to movement. The protruding rootsystem and trunks of overturned trees are obstacles to vehicles. The critical averagedistance between trees in forests where the trees are too big to be pushed over is about 3to 5 meters (10 to 16.5 feet), depending upon whether the trees are regularly orirregularly planted. Although this distance may be wide enough for the vehicle to passthrough, in most cases there is no room for turning. Reconnaissance is especiallyimportant as a source of vegetation information for two reasons. First, two of thecharacteristics--the size of trees and the distances between them--are seldom recorded.Second, the size and distances frequently are difficult to determine from aerialphotography. Tree blowdown during nuclear attack will present significant mobilityproblems. Forested areas which have been affected by blast will be impassable to trackedand wheeled vehicles.

CULTURAL FEATURES

Cultural features are constructed works such as stone walls, hedgerows, dikes, canals,drainage ditches, embankments, cuts, fills, and built-up areas, as well as damaged orabandoned vehicles and mobile equipment. Some of these features are considered underthe slope factor, some under streams, and some--such as built-up areas--are frequently notevaluated in cross-country movement studies. Cultural features are treated as a separatefactor here to insure that they are not overlooked in evaluating terrain for cross-countrymovement. The obstacle value of a cultural feature depends on its size or extent, location,and construction. Large cities and towns that have many masonry buildings locatedastride principal communication routes can become obstacles of considerable importancebecause they can be reduced to rubble and restrict enemy movement. Even if gaps arecleared through the rubble and debris, movement is still canalized. The natural obstaclevalue of built-up areas can be readily reinforced, and those properly located to controlapproaches or key terrain can be developed into formidable strongpoints.

CRITICAL FACTORS OF CULTURAL FEATURES ARE SIZE, LOCATION, AND CONSTRUCTION.

Roads and railroads

Another extremely important cultural feature is the road and railroad net. It will have afundamental influence on an attacker's choice of approaches, because-- • The anticipated rates of advance will force the attacker (except the lead elements of his main body) to move on roads, unless combat or imminent combat forces him to deploy into tactical formations. • The road net is critical to the movement of the attacker's following echelons. • The attacker must have a well-developed road and/or railroad net for his logistical support.Every break in this road and railroad net creates an obstacle to an attacker's rapid tacticalmovement, the movement of his following echelons, and his logistics. If the break is inhis division rear or farther back, its effect is interdiction. Corps and division obstacleplans, as well as denial plans, must consider this effect. Further, a highly developed roadand/or railroad network with its numerous cuts, fills, and embankments creates obstaclesto transverse movement which are comparable in extent to the drainage network. TheGerman autobahn system is an excellent example.

Minor cultural features

Minor cultural features also can act as deterrents or obstacles to movement. A stone wallor hedgerow is a serious obstacle, unless the sheer weight of a vehicle can push throughit. Accordingly, the height and thickness of such walls or hedgerows, as well as the heightof embankments and the slope on either side, determine obstacle value. Embankmentsmore than 3 meters (10 feet) high with side slopes greater than 45 percent can be seriousobstacles. Cuts have similar significance. Large gravel pits, quarries, or areas where stripmining has taken place may present obstacles or traps for vehicles. These, too, must beevaluated, particularly with respect to slope and soil characteristics.Streams or drainage ditches that appear insignificant on a 1:50,000 scale tactical mapmay be of significant value in canalizing or slowing enemy movement. They are easilyreinforced and can be integrated into the overall obstacle plan with only small amounts ofeffort expended. Although most of the minor cultural features can be interpreted from airphotos, and many may be shown on topographic maps, the features' dimensions, whichdirectly affect cross-country trafficability, are difficult or impossible to determine fromphotos and maps. Thus, cultural feature information that may be most relevant to cross-country movement is frequently available only through over-the-ground reconnaissanceor from terrain teams.

CLIMATE

Climate and weather both significantly affect cross-country movement, although theireffects are usually indirect, and their influence is variable in duration and difficult topredict. Climatic influences are usually reflected in the nature of the terrain and obstacles.To a large extent, climate controls soil moisture, and thus soil strengths. It alsodetermines basic river and stream characteristics. Some easily overlooked direct effectsof climate are important. Fog and haze, common in some areas, significantly affectweapons employment and can retard or even prevent movement. Dust storms andsnowstorms have the same effect.

FOG, HAZE, AND

BLOWING SNOW CAN BE EFFECTIVE OBSTACLES.

Seasonal weather patterns are important. An attacker anticipating a quick victory maychoose to strike at any time of the year. Existing obstacles should be evaluated on thebasis of the seasonal weather conditions to determine their obstacle value.The ability to evaluate terrain and properly assess its obstacle value provides a significantadvantage to the commander who does it well. A good analysis enables the commanderto determine avenues of approach, key terrain, and best areas for weapons employment. Italso provides the commander a beginning for the obstacle plan. Full use of existingobstacles will help in conserving precious manpower and logistical effort necessary toemplace reinforcing obstacles.

COMBINED EFFECTS

The preceding paragraphs have discussed the individual principal terrain factors affectingexisting obstacles. Usually, their combined effect is far more important and considerablymore difficult to define. Slopes combined with vegetation and/or soil conditions limitvehicular mobility far more than any one of these factors alone. The obstacle effectbecomes apparent long before any of the individual factors reach their critical values. Thetank's weight magnifies the effect of even a slight rise by reducing its speed. Forexample, even though a tank can push over a tree 25 centimeters (10 inches) in diameteron level ground, the same tree will stop the tank on a slight uphill slope. Further, thecombined effect of several less-than-critical features or factors can stop the enemy'sarmored vehicles. Closely spaced trees much smaller than 25 centimeters (10 inches) indiameter will stop a tank even on level ground. Even more important is recognizing thatthe critical values discussed in the preceding paragraphs are the limits for haltingmovement. Lower values of slope or smaller trees, steps, ditches, and so on, will severelyslow the enemy's movement. A high frequency or density of features that are less thancritical can severely reduce, although not stop, the enemy's speed. For example, a tankmay eventually force its way through one of West Germany's densely-cultivated foreststhat has not reached full growth, but only by repeated lunges at a very slow effective rateof movement. To consider another example, every tanker knows how effectively anumber of terraces or ditches, each individually crossed, can interfere with movement. Itis not always necessary to completely stop the enemy's armored vehicles. Frequently, it ismore desirable to slow but not stop him. If the goal is to lead enemy formations along acertain passage or in a particular direction--into a desired engagement area for example--or to lure enemy tanks to expose their less-heavily armored flanks, then it may bepreferable not to stop him.

LESS-THAN-CRITICAL TERRAIN FEATURES CAN SLOW BUT NOT STOP ENEMY TANKS.

Other effects, although not necessarily obstacle effects, also must be considered. Theeffect of slopes, in conjunction with limited depression and elevation of the tank's maingun, is important in siting both antitank weapons and obstacles. A steep cross-slope alsomakes it more difficult for the gunner to rapidly deliver accurate fire, thus giving thedefender a relative advantage.Finally, terrain factors are evaluated in light of the movement of a combined armsformation, and not of one tank. Threat forces attack in relatively fixed formations.Natural or cultural obstacles that stop or slow a part of the formation will thus affect themovement of the entire formation, either to slow it or change its direction. This effectemphasizes the slowing ability of less-than-critical terrain factors or features. It alsoprovides the basis for siting many of the defender's reinforcing obstacles. The effect ofcombinations and variations of natural or cultural obstacles makes their evaluation acomplex skill, one that requires experience and practice to develop its full potential.

REINFORCING OBSTACLES

The previous section developed the concept of existing obstacles as a part of the terrain,and discussed their characteristics, identification, and analysis. This section considers theuse and types of reinforcing obstacles that the commander can use to knit together,strengthen, and extend existing obstacles in support of his tactical plan. Reinforcingobstacles are those obstacles specifically constructed, emplaced, or detonated to extend orimprove the effectivess of existing obstacles. They are placed for the purpose ofanticipated military action or action already in progress.

REINFORCING OBSTACLES ARE CREATED TO SERVE A PLANNED OR ON-GOING MILITARY ACTION.

Many existing obstacles tend to be lengthy (rivers, canals) or broad in extent (forests,swamps). They can often more accurately be described as obstacle areas rather than asingle obstacle. Existing obstacles are highly variable in effectiveness from place to placeand have frequent gaps or openings between, and lanes (roads, bridges) through or overthem.

REINFORCING OBSTACLES TIE TOGETHER TO STRENGTHEN AND EXTEND EXISTING OBSTACLES.

After thoroughly examining existing obstacles and obstacle areas, and then determiningtheir relative stopping power, the commander has a much better feel for the use ofreinforcing obstacles. Given the general tactical plan, time, logistic support, andmanpower, the commander is able to add reinforcing obstacles to strengthen the terrain.Reinforcing obstacles normally are used to close gaps and block or close the lanes in theexisting obstacle areas, or to enhance the obstacle value of the terrain. In some cases, theyare used to extend natural obstacles or create obstacles or obstacle systems in opencountry.The nature and extent of reinforcing obstacles is limited only by the imagination of thecommanders or engineers who design them and the soldiers who emplace them. They arealso limited by the logistic effort required. Reinforcing obstacles can range from massivesystems such as the beach defenses constructed on the French coastline during WorldWar II, or the extensive antitank obstacles in the 1973 Middle East War, to a road crateremplaced by an engineer squad. Reinforcing obstacles can vary greatly in type, methodof emplacement, and logistic and manpower requirements. Reinforcing obstacles can bebroadly categorized by the following types: • Demolition. • Constructed. • Land mines. • Contamination. • Expedient.These categories are not mutually exclusive--some obstacles appear in more than onecategory and some (such as mines) are commonly used to strengthen others.

DEMOLITION

Demolition obstacles are created by the detonation of explosives, including nuclear

explosives. Demolitions are commonly used to create reinforcing obstacles. There aretwo types of demolition obstacles, preliminary and reserved. Preliminary demolitionobstacles are not absolutely critical to the tactical commander's plan, and do not require aformal written demolition order. They can be detonated as soon as they are prepared or asthe tactical situation dictates. Reserved demolition obstacles are critical to the tacticalcommander's plan, and require a formal written demolition order. They are detonatedaccording to the instructions in the order. Chapter 4 provides complete details on reserved demolition obstacles. Some typical uses of demolition obstacles are: • Blowing craters in roads, airfield runways, taxiways or parking areas, and railroads. • Destroying bridges or tunnels. • Demolishing buildings to create rubble. • Flooding areas by destruction of dams or locks. • Creating abatis by tree blowdown. • Blowing ditches using solid or liquid explosive. • Detonating prechambered roads and bridges.

CONSTRUCTED

Constructed obstacles are those reinforcing obstacles that are built by soldiers andmachinery, generally without the use of explosives. Typical examples are: • Wire. • Tank ditches. • Log cribs. • Steel "H" beam post obstacles. • Falling or tumble blocks. • Dragon's teeth, hedgehogs, and tetrahedrons. • Nonexplosive abatis.Constructed obstacles generally require extensive amounts of one or all of the following: • Manpower. • Equipment. • Material. • Time.Soldiers and construction equipment can be exposed to all types of enemy fire whenemplacing constructed obstacles. Constructed obstacles should be emplaced prior to thestart of the battle, or a terrain feature away from direct engagement areas, so thatobserved fire cannot disrupt the emplacement process.

LAND MINES

Reinforcing obstacles other than minefield are primarily designed to enhance the firesand kill ratio of antitank weapons. Mines and minefield perform this function as well askilling or destroying enemy vehicles and personnel.Mine warfare is undergoing a tremendous evolutionary process. Significantimprovements have been made in mines and mine delivery systems. We have thecapability to quickly emplace mines anywhere on the battlefield using various deliverysystems. Mines have changed to the point where we now have to discuss them in twoseparate categories, conventional and scatterable mines. This categorization is requireddue to the different capabilities, employment techniques, and delivery means of each.Both categories of mines have a distinct place on the battlefield and complement eachother.Conventional mines are those mines not designed to self-destruct. Conventional minesare designed to be directly emplaced by hand or by mechanical mine planting equipment.They can be buried or surface-laid. Conventional mines can be emplaced in a classicalpattern or without regard to pattern as the tactical situation dictates.Scatterable mines are those mines which are designed to self-destruct after a set periodof time. With the exception of the Wide Angle Side Penetrating Mining System(WASPMS) which is directly emplaced, scatterable mines are remotely delivered byground systems, artillery, helicopters, and high-performance aircraft. The term"scatterable" refers to selfdestructing mines. It should not be used to describeconventional mines which have been laid without regard to pattern.Scatterable mines have added a new dimension to mine warfare and the battlefield. Thetraditional concept of large linear minefield across contested areas between two forces isno longer viable, except possibly in desert warfare. Future battlefields will contain manysmaller mined areas placed in response to enemy dispositions and movement. Scatterablemines will be employed against enemy units anywhere on the battlefield. Scatterablemines can be emplaced by a variety of delivery systems ranging from mechanical andexplosive ground systems to artillery, helicopters, and high-performance aircraft.Scatterable mines significantly reduce manpower requirements associated with minewarfare. Scatterable mines are also smaller, lighter, and more lethal. They offer areduction in logistical requirements due to reduced bulk and weight. NOTE: The reader should beware of the terms "scatterable" and "Family of Scatterable Mines (FASCAM)" when referring to specific systems and their employment. Those generic terms are only applicable in the most general sense when discussing doctrine. Whenever possible, refer to the specific delivery system and the characteristics of that system, rather than the generic term.Mines are used extensively where the existing obstacle structure is weak or nonexistent.They should also be used with other reinforcing obstacles, such as tank ditches, to makebreaching and clearing more costly and time-consuming to the enemy.Since all scatterable minefield systems provide great flexibility to maneuvercommanders, there will be extensive demands for them. Commanders and engineersshould plan and carefully assign priorities. Available systems must be used for the mostcritical needs. Employment must be closely coordinated with obstacle plans, fires, andthe scheme of maneuver. Coordination with fire support planners, aviation staff officers,and air liaison officers is essential to insure prior planning to execute minefieldemplacement missions on short notice. Planning and employment of scatterable mines, aswell as conventional mines, are discussed in depth in chapter 5.

CONTAMINATION

Contamination can be either nuclear or chemical in nature. Both types are difficult topredict and control because they depend on winds for placement, and are subject toweather and other environmental factors. The United States has renounced the first use ofchemical weapons. Further, the most predictable source of nuclear contamination,Atomic Demolition Munitions (ADM), is subject to the same restrictions as all nuclearweapons and may not be available for use when needed. If an ADM is used for cratering,there will be both close-in radiation and fallout, each effectively contaminating an area ofreasonably predictable extent. Threat doctrine considers the use of both nuclear andchemical weapons, and threat forces train for operations in contaminated areas. Thepresence of contamination and its effects on the battlefield must be anticipated.

EXPEDIENT

The potential of expedient obstacles is almost unlimited. They place a great premium onimagination and ingenuity in the use of available materials and other resources, thusavoiding the logistic burden associated with all other types of obstacles. All sorts ofnonstandard log obstacles can be built. Their complexity depends upon the time andpersonnel available. Junked or destroyed cars and trucks or other debris can be spread toblock an open area or, if the region is rocky, earthmoving equipment can be used todistribute boulders to block tanks. Selected trees can be pushed over to make an abatis orto strengthen a wooded area where tree spacing might otherwise allow armored vehiclesto pass. Short ditches can be cut in lieu of craters. Material can be pushed up to form aroad block. Equipment can steepen or deepen stream banks, gullies, or other breaks in theterrain to make expedient tank ditches. Trees can be cut or broken with a variety ofvehicles or pieces of equipment. They can also be pushed or pulled down by winches toform expedient abatis or strengthen wooded areas. The M9 Armored Combat Earthmover(ACE), dozers, loaders, and many other pieces of equipment can also be used.The wreckage of destroyed towns, cities, or industrial areas offers a source of materials tobe used in making expedient obstacles. If permitted, limited controlled flooding can beused, not only to inundate areas, but also to create soft or slippery areas where soilconditions would make this possible. Timber bridges can be burned, and controlled firescan be used to create obstacles in other ways. For example, igniting the brush in a brush-filled ditch, at the proper time, can make an effective obstacle. If available, ice and snowcan be exploited to create effective obstacles.By their nature, expedient obstacles substitute locally available materials and soldierlabor for a logistical requirement. All that is needed is the imagination to recognize thepotential of available materials. PRINCIPLES OF OBSTACLE EMPLOYMENT

AirLand Battle doctrine gives the commander fighting the battle a complete range ofdefensive and offensive options. A static type defense can be used to focus upon terrainretention using firepower from fixed positions to deny terrain. The commander can alsodefend using a dynamic defense that focuses upon maneuver to destroy enemy forcesrather than retain specific terrain.The static and dynamic defensive frameworks are the extremes of the spectrum.Typically, the commander may choose to combine both the static and dynamic forms inorganizing the defense based upon the factors of mission, enemy, terrain and weather,time, and troops (METT-T).Whatever the concept, organizing the defense must be carefully matched to the terrain.The engineer is the principal element in reinforcing the terrain to best complement themaneuver commander's plan. The engineer and the maneuver commander mustcoordinate throughout the planning and battlefield preparation sequence to insure unity ofeffort and maximum effectiveness of obstacle employment.Terrain reinforcement techniques must be employed along the depth of the enemy'sformation and avenues of approach where existing terrain places him at the greatestdisadvantage. Use of reinforcing obstacles is the principal method of terrainreinforcement. Reinforcing obstacles must be used in conjunction with the existingobstacles and the commander's plan. Reinforcing obstacles have three primary purposes:1 Enhance the effectiveness of friendly antitank fires.2 Delay the enemy's advance, upset his timing, disrupt and channelize his formations, anddelay or destroy follow-on echelons.3 Enhance friendly economy of force measures.Obstacles must be covered by fire if at all possible. They should be located within theeffective range of friendly direct fire antitank weapons. Their locations must be carefullycoordinated with the location of battle positions and direct and indirect weapons. Wewant to engage the enemy at the maximum effective range of our antitank weapons, andforce him to breach and fight his way through a series of obstacles while under intensefire. Each obstacle delays some part of the enemy's leading elements.

AN OBSTACLE CAN SIGNIFICANTLY ENHANCE ANTITANK FIRES.

The coordinated use of obstacles can delay and disrupt enemy formations, and also forcethem into the primary fields of fire of our tanks and other antitank weapon systems, orprevent escape from such an engagement area. The enemy is forced to move on thebattlefield in conformance with the friendly commander's plan.

The skillful use of obstacles to channelize the enemy is a vital factor. Once the enemyforce maneuvers into the engagement area, it is held there by other groups of obstacles,and still others may be used to close the trap behind it. (Scatterable mines are ideal for thelatter purpose.) Other obstacles are used to separate the enemy's leading elements fromreserves or following echelons, thus precluding reinforcement.Mutually supporting obstacles serve other important purposes. They can be used in theeconomy of force role to strengthen a naturally strong existing obstacle area so that itneed only be lightly defended, thus freeing forces to be concentrated elsewhere.Similarity, obstacles can be used in conjunction with mobile forces to protect flanks andother lightly defended areas. This is a particularly important role in view of the threatdoctrine of penetration and envelopment, and the overall dispersion of forces on thebattlefield.Regardless of the type defense employed by the tactical commander, there are five basicemployment principles for reinforcing obstacles:1 Reinforcing obstacles support the maneuver commander's plan.2 Reinforcing obstacles are integrated with observed fires.3 Reinforcing obstacles are integrated with existing obstacles and with other reinforcingobstacles.4 Reinforcing obstacles are employed in depth.5 Reinforcing obstacles are employed for surprise.1 Reinforcing obstacles support the maneuver commander's plan. Reinforcingobstacles must be planned and emplaced to support the tactical plan. Obstacles other thanmines emplaced outside the range of friendly weapons are of little use. Reinforcingobstacles that do not accomplish one or more of the basic purposes of reinforcingobstacles are also of little value. Engineers must be completely familiar with the tacticalplan, the existing terrain, and the maneuver commander's intentions. Only then can fulladvantage of the multiplier value of integrating obstacles and fires be realized.

2 Reinforcing obstacles are integrated with observed fires. Obstacles are used todevelop engagement areas in which enemy maneuver is restricted and slowed, therebyincreasing the hit probability of friendly direct and indirect fires. The tactical commanderand the engineer site the weapons and obstacles which offer the best relative advantage,and consider terrain configuration and the effective weapons range. Special attentionmust be given to locating obstacles to complement the fires of Dragon, tanks, and tube-launched, optically tracked, wire-guided missiles (TOWs). Since TOWs have a greatermaximum effective range than Threat tanks, it is to our distinct advantage to site part ofthe tactical obstacle system to capitalize on that difference. Generally, the greatestrelative advantage accrues when the obstacle is at the maximum range possible andconsistent with visibility conditions and the tactical plan. Observed indirect fires are alsoused in conjunction with obstacles against enemy vehicles and infantry out in the open.Observation and adjustment of fires are essential if the full advantage is to be developed.At the same time, fires serve to protect the obstacle by making it costly to breach orbypass. With rare exceptions, obstacles that are not covered by fire are little more than anuisance to the enemy's leading elements.Keep in mind, however, that the principal purpose of integrating obstacle locations withfire is to enhance the effectiveness of those fires--a significant combat multiplier effect ofobstacle use.

3 Reinforcing obstacles are integrated with existing obstacles and with otherreinforcing obstacles. Reinforcing obstacles are sited to take the maximum advantage ofexisting obstacles. They are placed where they can close the gaps or openings betweenexisting obstacles and/or close any passages through them. The road network must bedestroyed and the inherent natural pattern of cross-country movement should bedisrupted. The first obstacles planned are bridge demolitions, road craters, abatis, andpoint or small minefield that tie together the existing obstacle areas and close thepassages through them. Other reinforcing obstacles are then located to strengthen andextend the existing obstacle areas and block major corridors. Taking advantage of theexisting obstacles reduces the resources required to quickly obtain an effective obstaclesystem. Effective reinforcement of existing obstacles also enhances economy of forceoperations by permitting friendly forces to concentrate on more trafficable terrainapproaches.Individual obstacles must be sited and designed to tie in with existing obstacles or witheach other. An obstacle that can be bypassed immediately is worthless. Each individualobstacle must be carefully designed for the exact location it will occupy, and mustoverlap on each side with the existing obstacle it will complete. The critical design widthof an obstacle is the distance from an existing obstacle to another existing obstacle (or toanother reinforcing obstacle), and not the width of a road or highway through the existingobstacle.Another major design consideration is that the reinforcing obstacle does not need to bestronger than the integrated existing obstacle. The obstacle should be no more difficult tobreach than it is to get around. If the enemy could force his way through the existingobstacle in the immediate vicinity in 10 minutes, it would be wasteful to construct areinforcing obstacle requiring 40 minutes to breach. The effort and resources used toobtain the last 30 minutes of breaching time are desperately needed elsewhere. Althoughthe delay or breaching time associated with a particular obstacle may be difficult todetermine, this principle must nevertheless be kept in mind to obtain the most use ofavailable resources.

Reinforcing obstacles are integrated with each other to assure that probable bypass routesare closed. For example, destruction of a major highway through a wooded area is largelyineffective if any nearby road or opening that offers a ready bypass route is left open.(Such destruction could be highly effective, however, if friendly forces were seeking todivert the enemy along that bypass route.) Reinforcing obstacles can also be used to closegaps and lanes in other reinforcing obstacles. For example, a crater can be used to close aroad left open through a minefield when all friendly troops have cleared.

4 Reinforcing obstacles are employed in depth. A series of simple obstacles arranged

one behind the other along a probable axis of enemy advance is far more effective thanone large, elaborate obstacle. Restricting the design of obstacles to correspond with thestrength of the existing obstacle (as previously discussed) helps to conserve effort anddirect it toward executing obstacles in depth. Obstacles must not be located too closetogether so only a single enemy response is required. They must be far enough apart thateach will require a new deployment of the enemy's counterobstacle forces and/orequipment. The distance between obstacles will depend on the terrain and the obstacleeffort available. Proper use of obstacles in depth wears the enemy down and significantlyincreases the overall delay. At each new obstacle, he incurs losses and is forced to stopand react. This wearing down effect is psychologically significant. The desired effect isto degrade the enemy soldier's will and induce a feeling of hopelessness. This can bedone by convincing him that, beyond each new obstacle (with its attendant loss ofpersonnel and equipment), there awaits another obstacle with a similar cost; and, beyondthat one, yet another, and so on. Another reason for using a greater number of lesselaborate obstacles is that each one forces the enemy to expose his limitedcounterobstacle equipment and troops to loss. When the counterobstacle resourcesinitially allotted to the leading elements have been destroyed, the enemy's movement willbe severely slowed until new counterobstacle units can be brought forward.

5 Reinforcing obstacles are employed for surprise. Using obstacles so as to obtain

surprise is one means available to the commander to retain a degree of initiative evenwhen defending. Scatterable mines permit rapid mining anywhere in the battle area,confronting the attacker with a completely new situation almost instantly. The self-destruct feature of the scatterable mine also provides surprise--a friendly counterattackmay be launched through an area that was mined prior to the attack but where the mineshave just self-destructed.More conventional ways to obtain surprise are also available and should be used. Theyinclude the sudden detonation of concealed obstacles in front of the attacking enemy orwithin his formations. Conventional ways also include the use of phony obstacles tomislead the enemy as to the pattern and extent of the friendly obstacle system. Anobvious pattern of obstacles would divulge locations of units and weapons. Friendlyforces must avoid readily discernible, repetitive patterns. By varying the type, design, andlocation, the enemy's understanding and breaching of our obstacle system is made moredifficult. Extensive use of obstacles can make a major contribution to this effort.Reinforcing obstacles which complement the existing obstacle value of the terrain, andare designed and emplaced to support the maneuver plan, are an effective "combatmultiplier." Tactical commanders and engineers must exploit the full value of obstacles.

SUMMARY

Obstacles are classified as either existing or reinforcing. Existing obstacles are thosenatural and cultural restrictions to movement that are a part of the terrain when battleplanning begins. The ability to recognize and evaluate the obstacle potential of the terrainis critical to planning the battle. Reinforcing obstacles are constructed, emplaced, ordetonated to knit together, strengthen, and extend exisiting obstacles.Reinforcing obstacles must be integrated with friendly observed fires, the friendlycommander's maneuver plan for both the enemy and friendly forces, and existing andreinforcing obstacles. Reinforcing obstacles must also be arrayed in depth and employedfor surprise.Mines are generally the most effective type of obstacle because they also inflict losses onthe enemy, and their use is highly flexible. The Family of Scatterable Mines (FASCAM)vastly increases this flexibility, making the creation of rapid minefield possible.Obstacles are also used to delay and disrupt an attacking force, upset the enemy's timingand plans, and divert him into engagement areas and be destroyed. Obstacles can delay ordestroy follow-on echelons.Obstacles can significantly enhance the effectiveness of our fires and thus our ability towin the battle.Chapter 3

COMMAND AND CONTROL

Countermobility activities are planned and executed to defeat the enemy's ability tomaneuver. This chapter addresses the coordinated development of obstacle plans atvarious levels of responsibility. Procedures for positive control of reserve obstacles andpreparation of demolition orders are also included. LEVELS OF RESPONSIBILITY RESERVE OBSTACLES SUMMARY

LEVELS OF RESPONSIBILITY

An effective command and control system is a must for countermobility activities. Theprimary goal is to make the enemy go where we want, when we want, at speeds wedictate. We want to accomplish that goal with little or no effect on the ability of friendlyforces to move and maneuver. To do so requires a command and control system thatemphasizes long-range planning, centralized control, and decentralized execution.Centralized control is necessary in the planning of countermobility activities to insurethat the obstacle plan is integrated with and supports the overall tactical plan. Seniorcommand levels must dictate obstacle zones, obstacle-free areas, and reserve obstacles inthe planning process. The specific type and placement of those ground obstacles are bestaccomplished by the level that can actually conduct a ground reconnaissance.

CORPS OBSTACLE PLAN

Centralized control of countermobility activities normally begins at the corps level withthe corps obstacle plan. The corps obstacle plan is general in nature and concerned withthe employment of obstacles as a part of a specific tactical operation. The obstacle plansupports the corps commander's concept of the operation and integrates the terrainaspects of the operation with the tactical plan. Through the allocation of engineer supportand logistics, the corps commander shapes the countermobility efforts of the division byweighting those areas viewed as most critical. The corps obstacle plan provides aframework for the division plans. The corps obstacle plan can and will normally includethe following items: • Assignment of areas of responsibility. • Designation of any specific obstacles vital to the corps as a whole. • Completion times for all or any portion of the obstacle plan when deemed necessary; however, completion times can be specified later. • Gaps, lanes, and important routes to be kept open and areas important to the commander for tactical and combat service support operations, as well as for future operations. Gaps and lanes are specifically designated at the lowest level practicable in consonance with the mission of the command. • Allocation of engineer support, materials, transportation, and equipment. • Reporting instructions to insure all headquarters in the chain of command keep abreast of the obstacle situation and plan their operation accordingly. As a minimum, reports to division level must include target or obstacle identification, location, and status. • Coordination required between adjacent units to insure critical points (such as common boundaries) are effectively covered, gaps and lanes are properly located, sufficient in number, and not closed for passage before the time required. • Procedures for employment of scatterable mines to include provisions for air and artillery delivery, if not specified by standing operating procedure (SOP). • Limitations or restrictions on the employment of certain reinforcing obstacles such as minefield and booby traps, chemical contamination, and ADM. To guard against premature execution, restrictions may be placed on the employment of reinforcing obstacles. The corps may accomplish this by requiring subordinate units to request approval for the closure of specific gaps and lanes. The corps may also retain approval authority for clearance or release of control over specific routes prior to the destruction of bridges and other transportation facilities. The corps commander maintains surveillance over tactical operations and removes any restrictions imposed on the execution of obstacles as early as possible to give subordinate units maximum freedom in operations. • Limitations or restrictions on the emplacement of obstacles in a specific area. Corps may designate areas to remain obstacle-free, assuring the corps commander freedom of maneuver for counterattacks and reinforcing movements. • Limitations on, and conditions for, the destruction of facilities of strategic importance such as locks, dams, major bridges, and tunnels. • Instructions regarding the submission of detailed obstacle plans for approval.

CORPS OBSTACLE PLAN

PREPARED BY: Corps HQ

SCOPE: Comprehensive, coordinated plan which includes:

1 Responsibilities

2 General locations of unspecified obstacles

3 Specific obstacles

4 Special instructions, limitations, coordination, completion times

BASED ON: Guidance from higher HQ, tactical plan, maps,

aerial photos, terrain analysis, general recon of the area

The corps obstacle plan is a command and control means for the corps commander tocommunicate the countermobility concept to subordinates. Corps obstacle plans must beprovided to the Army Battlefield Coordination Element (BCE) which is the land forcescoordinating agency with the Air Force Tactical Air Control Center (TACC). Thiscoordinating and sharing of information is accomplished for several reasons: • Assist USAF targeting efforts. Knowing the location of land force emplaced obstacles will assist the Air Force in attacking concentrated enemy elements created by obstacle employment. • Prevent duplication of effort by air and land forces. • Assist ground movement by USAF elements such as radar and logistic elements. As the corps obstacle plan is modified or executed, continuous information will be provided by the corps to the BCE which will have the information available for TACC planning. Known locations of enemy obstacles will be included.

DIVISION OBSTACLE PLAN

The corps plan/order is received at division and analyzed for specified and implied tasks.Once this is accomplished, the division obstacle plan is developed in two stages, initialand final.

Initial plan

An initial plan, based on the corps obstacle plan, division tactical plan, fire plans, maps,terrain analysis, and reconnaissance, is disseminated to the brigades and othersubordinate units as quickly as possible to allow time for obstacle selection on theground. This must be done in conjunction with selecting fighting positions and locatingweapons systems. The initial plan will include an overlay showing, as a minimum, targetsdirected by corps or higher headquarters and obstacles of such importance as to bespecified by division. The plan may also specify obstacle zones to be developed bydesignated unit(s). In addition, the plan will assign responsibilities and, where necessary,priorities; allocate obstacle materials to include scatterable mines; and generally includeas much of the information described for the corps plan in whatever available detail asappropriate.

DIVISION OBSTACLE PLAN

PREPARED BY: Division HQ

INITIAL SCOPE:

1 Concept and detailed guidance

2 Specific obstacles directed by corps or division,

responsibilities, and obstacle priorities

BASED ON: Corps obstacle plan, division tactical plan, fire

plans, maps, aerial photos, and general recon of the sector

FINAL SCOPE: Completes the cycle. Specifically identifies

each obstacle in the division obstacle system to include:

1 Target type

2 Target number

3 Coordinates

4 Priority

5 Completion date/time 6 Responsible unit

7 Special instructions (execution times/authority)

UPDATE BASED ON: Brigade plans and input from other units

following ground recon and obstacle selection

Final plan

After the brigades develop their obstacle plans in detail, and other units develop assignedportions of the division obstacle plan by selecting individual obstacles, these subordinateplans are then incorporated by division with the initial plan to produce the final plan. Theplan will normally be issued as an annex to the division operations order.When time is extremely limited, the division plan may never develop beyond the initialconcept plan. Conversely, when adequate time is available, the division plan will besubmitted to corps and may be incorporated into a republished corps obstacle plan. Thecomplete division obstacle plan should hot be carried forward of division headquartersbecause of the danger of compromise. Division provides each brigade with extracts of thedetailed plan to include pertinent portions of the plans of adjacent brigades.

BRIGADE OBSTACLE PLAN

Brigades and comparable units develop a detailed obstacle plan, within the guidanceprovided by division, based on their tactical plans and detailed terrain reconnaissance. Tobe effective, obstacle plans must be integrated at maneuver unit level. This process isdescribed in chapter 4. If combat is imminent, preparation of obstacles beginsimmediately without waiting for approval of the obstacle plan. Obstacle construction andobstacle plan development continue con-currently. Final brigade obstacle plans include: • Location and type of each obstacle, including those specified by higher headquarters. • A timetable and priority of construction for obstacles. • Specific orders stating under what conditions and by whose authority reserve obstacles are to be executed. • Routes to be kept open in accordance with the tactical and logistical plan, including those specified by higher headquarters. • Exact location and extent of gaps and lanes, including those specified by higher headquarters.

RESERVE OBSTACLES

Reserve obstacles (non-nuclear) are those obstacles or demolition targets the commanderdeems critical to the tactical plan. The authority to execute the obstacle is reserved by theauthorizing commander through a formal order known as a demolition order. Reserveobstacles must be carefully selected. Their proper execution requires a manpowerallocation that could be used elsewhere if it is not required to guard and execute a reserveobstacle. If not executed timely and properly, reserve obstacles could be catastrophic tothe tactical plan or operation. An excellent example of a failure to execute a reserveobstacle is the Remagen bridge in World War II.

REMAGEN BRIDGE

As Allied Forces advanced to the vicinity of the Rhine River in early March 1945,the Germans made preparations to demolish all bridges across that wide river.The German high command planned to use the Rhine as a moat to afford theirbeleaguered forces a badly needed rest. Each time the Allies attempted to capturea Rhine River bridge, the Germans methodically and efficiently destroyed it.However, at one bridge--the Remagen railway bridge--a confused situation wasripe for disaster.

The German bridge garrison at Remagen consisted of an understrength infantry

company, a handful of engineers, and a smattering of Volksturm or Home Guardunits. These elements were under the command of Captain Bratge, the infantrycompany commander. The engineers were commanded by Captain Friesenhan.Neither Captain Bratge nor Captain Friesenhan had specific instructionsconcerning the demolition of the bridge. The engineer commander had standingorders to execute the obstacle only upon the written order of the tacticalcommander (Captain Bratge). At dawn on 7 March 1946, a steady stream ofdisorganized German units and stragglers were fleeing l cross the bridge. Thesesoldiers brought stories of large American forces approaching rapidly from thewest. Alarmed, Captain Bratge attempted to contact higher headquarters forinstructions. He was only able to reach a duty officer at Army Group B whoassured him that headquarters was not concerned about the situation at Remagen.At 1115 hours, Captain Bratge was approached by a German officer whoidentified himself as Major Scheller. Major Scheller stated that he had been sentby the commander of LXVII Corps to assume command at Remagen. The Corpswas holding a bridge-head on the west bank of the Rhine, but the perimeter wasrapidly being forced toward Remagen. Once Captain Bratge had assured himselfof Major Scheller's identity, he gladly relinquished command. Unfortunately, thevehicle containing Major Scheller's radio had become lost enroute to Remagen;thus, he had no means of communication with higher headquarters and no specificinstructions.

Soon after 1300 hours on 7 March 1945, Major Scheller received reports thatAmerican forces had reached the bluffs over-looking the Remagen bridge. MajorScheller was reluctant to destroy the bridge because a German artillery captaininsisted his battalion and its guns were going to cross the bridge shortly. CaptainFriesenhan crossed to the west end of the bridge. He planned to execute a craterwhich had been emplaced some months before to prevent tanks from rapidlyreaching the bridge. Around 1600 hours. a company of American infantry andtanks appeared at the approaches to the bridge. On his own authority, CaptainFriesenhan fired the crater, then raced across the bridge to find Captain Bratgeand Major Scheller to get the order to blow the bridge. Enroute, he was knockedsenseless by a concussion from a tank shell. Fifteen minutes passed before heregained consciousness, continued across the bridge, and obtained approval to firethe demolition. Initially, Captain Friesenhan insisted on written orders, but thenrelented in the interest of time.

Captain Friesenhan turned the key to electrically fire the charge, but nothinghappened. He tried again and again with no results. He realized that the firingcircuit was broken. By this time, American machine gun fire and tank fire weresweeping the bridge. Repairs to the circuit were out of the question. A sergeantvolunteered to go out on the bridge and fire an emergency charge nonelectrically.The sergeant dashed out on the bridge, and returned on the run minutes later. Thecharges exploded, but when the dust settled, the bridge still stood. American FirstLieutenant Karl H. Timmerman, commander of A Company, 27th ArmoredInfantry Battalion, and his soldiers rushed across the bridge. They established thebeginnings of a bridgehead which would enable US forces to transport 8,000soldiers, including one tank battalion, across the Rhine in the next 24 hours.Captain Friesenhan and Captain Bratge were captured. Major Scheller and threeother officers were tried by a German military tribunal, and were executed by afiring squad.

Some obviously glaring errors which proved extremely costly to the German Armyincluded: • Insufficient guard force. • Inadequate communication. • Confused instruction on when and on whose order the bridge was to be blown.

EXECUTION OF RESERVE OBSTACLES

A reserve obstacle must have positive written information and instruction on thefollowing items: • Who is the authorizing commander? • Who, if anyone, is to guard the obstacle until it is executed? • Who prepares and executes the obstacle? • Under what circumstances is the obstacle to be executed?There are three primary players involved in the proper and timely execution of reserveobstacles; namely, the authorizing commander, the demolition guard commander, and thedemolition firing party commander. Authorizing commander

The authorizing commander has overall responsibility. The authorizing commander maybe a corps, division, brigade, or any other commander who deems that a particular targetor obstacle is so critical to the tactical plan that its preparation, protection, and executionupon order are insured.

Demolition guard commander

The demolition guard commander is the onsite commander who takes orders from theauthorizing commander and who is responsible for the successful execution of the reserveobstacle. The demolition guard commander is also responsible for security, preparing theobstacle, and giving the order to arm and execute the obstacle once the authority toexecute has been received.

Demolition firing party commander

The demolition firing party commander receives orders from the demolition guardcommander and is in technical charge of the preparation and firing of the reserveobstacle. The demolition firing party is normally comprised of engineers.The demolition guard and the demolition firing party can, in some circumstances, be oneand the same. The demolition guard must be of sufficient strength and size to protect theobstacle and prevent enemy capture prior to execution. Both the demolition guard anddemolition firing party must keep the target in sight at all times. Positive communicationsmust be maintained between the demolition guard commander, the firing partycommander, and the authorizing commander.

TYPICAL RESERVE OBSTACLE SCENARIO

SUMMARY

The obstacle plans and updates are the principal command and control vehicles forobstacles planned and emplaced before the battle begins and during its early stages,Further employment of obstacles will be based on enemy movement and designed to fit aparticular tactical situation. Responsive communication, timely intelligence, and rapiddecision making are keys to successful obstacle employment after the battle has begun.Reserve obstacles can be vital to an operation. They must be planned and executedcarefully. The number of reserve obstacles should be held to the absolute minumum dueto the assets required to insure that they are guarded and executed properly.Chapter 4

OBSTACLE PLANS

Effective employment of obstacles is a key element in any tactical plan. Obstacles thatare sited properly provide the commander a significant advantage in both the offense anddefense. Planning and emplacing obstacles cannot be approached haphazardly. Theobstacle planning process must be systematic, coordinated, and fully integrated with thetactical plan. The logistic demands of obstacle employment must also be planned for andavailable at the proper place and time. All elements of the combined arms team must beinvolved in the obstacle planning and employment process in order to extract the greatestcost from the enemy. This chapter outlines the sequence and basic considerations forplanning and coordinating countermobility activities in various operations. PLANNING CONSIDERATIONS THE PLANNING PROCESS OFFENSIVE PLANNING CONSIDERATIONS DEFENSIVE PLANNING CONSIDERATIONS RETROGRADE PLANNING CONSIDERATIONS SUMMARY

PLANNING CONSIDERATIONS

Obstacle planning is serious business, and involves all elements of the combined armsteam. Obstacles must support present and future tactical plans, be logisticallysupportable, and fully coordinated. Some important factors to be considered are listedbelow. MISSION

The mission is the primary consideration in obstacle planning. The employment of

obstacles in support of a DEFEND mission would be significantly different from obstacleemployment in support of a DELAY or an offensive mission. The obstacle plan should betailored to support the mission of the organization and accomplish the objectives of thecommand.

DIRECTED AND RESERVE OBSTACLES

Directed and reserve obstacles are of prime importance to the overall mission and shouldbe planned first. Authority and time of execution must be known.

FUTURE PLANS

While obstacle employment is supporting the current mission, it should not impede futureplans or missions. This may not be completely possible in every instance. Emplacing anartillery delivered minefield upon an attacking enemy may be the right thing to do, eventhough an attack through the area was planned prior to self-destruction of the minefield.Pros and cons must both be considered.

ENEMY STRENGTHS AND WEAKNESSES

The obstacle plan should exploit the weaknesses of the enemy. If the enemy is short ofrapid bridging capability, a tank ditch may be a more effective obstacle than a minefield.If the enemy is low on diesel fuel or ammunition, attacking their trains and supply linesmay be the most effective use of obstacles such as scatterable mines.

TERRAIN AND WEATHER

These factors and their effects are critical in answering the following questions: Whereare good existing obstacles? Are they within the enemy's avenue of approach? Are theyeffective when tied in with reinforcing obstacles? Are they within range and fields of fireof friendly weapons? What are the anticipated weather conditions? Is the soil frozen? Isdigging possible? Can mines be buried?

AVAILABLE TIME, MATERIALS, MANPOWER, AND EQUIPMENT

Answers to these questions will dictate to a large degree the type and extent of theobstacle system, and also provide information on additional resources required and taskorganization. How much time is available to spend on battlefield preparation? Have therequired materials been ordered? Are they on hand? Is the manpower available for labor-intensive obstacles? Is earthmoving equipment available for tank ditches and otherequipment-intensive obstacles? Has the high diesel fuel consumption rate been plannedfor? EFFECTS ON THE LOCAL POPULATION

Cultural features are not destroyed unless the mission makes it absolutely necessary.These considerations are not inclusive. There may be many other important factors. Eachmission, operation, or battle phase will pose distinct requirements that must be consideredand planned for. Obstacles can be the difference between winning and losing. Theiremployment must be carefully planned and fully coordinated.Obstacles should be emplaced according to these general guidelines: • Obstacles should support weapon systems by slowing the enemy at the maximum effective ranges of our weapons systems, as limited by fields of fire available. • Obstacles should not impede our own mobility; or, if they do, they should be reserved targets or scatterable mines with a self-destruct time coordinated to future maneuver plans. • Obstacles must hinder enemy movement as we move from battle positions. • Obstacles are emplaced in as much depth as is feasible after considering the time, manpower, and logistical constraints. These in-depth obstacles are integrated into the battle position fire support plans, assist the commander in stopping the enemy within the MBA, and then assume the offense.

1 Analyze the mission. The mission is a clear, concise statement and purpose of the taskto be accomplished by the command. It tells the command the "who," "what," "where,"and "when" of an operation. Analysis of the mission is a critical item in planningobstacles. The "who" portion and accompanying task organization allocates resources todo the job. The "what" specifies the type operation such as "defend," "attack," or "delay.""Where" outlines the area of operations, and "when" specifies the time available andessentially establishes deadlines. During the planning phase, much or all of thisinformation will be verbal based upon commander and staff analysis of the missionreceived from higher headquarters. The estimate, eventual plan, and execution are basedupon tasks contained in the mission.

2 Analyze avenues of approach. Once the mission has been received and analyzed andthe basic objectives are known, the next step in obstacle planning is to determine avenuesof approach. Terrain analysis techniques and existing obstacle evaluation, as described inchapter 2, are performed. The commander must visualize the avenues of approach underall conditions, and determine the size of friendly or enemy forces those avenues cansupport.

good terrain analysis will show where the best areas are for friendly weapons to engagethe enemy. In offensive planning, the most likely areas where friendly forces couldexpect to be engaged by enemy direct fire weapons can also be ascertained. The analysisprocess is essentially the same in both the defense and the offense. Analysis of existingobstacle areas, fields of fire, and natural cover and concealment are key factors indetermining where to best engage the enemy or expect to be engaged.

4 Determine possible obstacle locations and types. Selection of engagement areas andbattle positions must be accomplished prior to planning reinforcing obstacles. Once thecommander has selected engagement areas and battle positions, then the commander andthe engineer select those reinforcing obstacles that accomplish the basic principles. Thisselection process is unconstrained, meaning that the commander and engineer will selectand site all the reinforcing obstacles necessary without regard for manpower, time, andlogistics. This selection process will determine what "needs" to be done in order for theobstacle system to be most effective. What "needs" to be done will usually require moreeffort than resources available. The process provides the commander and the engineerwith a method to establish priorities if resources are constrained.

5 Determine the commander's obstacle priorities. Once the unconstrained obstacle

estimate has been accomplished, the commander can establish priorities for obstacles. Byseeing what "needs" to be done, the commander can choose those obstacles that must beemplaced. Through this process, the engineer is given direction to employ resourcesknowing the effort is expended on those obstacles most critical for accomplishing thecommand's objectives. The type, proposed location, and purpose of the obstacles willdepend on an offensive or defensive plan. However, the basic thought process remainsconstant.

6 Determine resources. The commander and the engineer consider the assets availableto construct, guard, and execute the obstacle plan. Engineer assets are limited, and thepriority of work maybe given to only a portion of the planned area of operations. Theengineer takes the commander's priorities and makes an estimate based upon time,manpower, equipment, and logistics. The engineer must know how much of eachresource is required to emplace and execute a given obstacle. This estimate is based upontype of obstacle, soldier experience, state of training, and condition of equipment.Standard obstacles (appendix D) may be used to assist in the estimating process. They areonly a guide and should be altered according to existing conditions at the time of theestimate.Another factor in the engineer estimate is the commander's decision on who will guardand detonate preliminary demolition obstacles not detonated immediately afteremplacement. Essentially, the commander has two choices--either use engineer soldiers,or soldiers from maneuver units. If engineers are used, then engineer assets are used upquickly, thus limiting the number of obstacles that can be emplaced as the battleprogresses. The same can be said for using maneuver units to guard and detonateobstacles. This difficult decision must be made early enough for the engineers andmaneuver units to properly plan. In any case, the target turnover process must be trainedand rehearsed during combined arms training so the commander has some latitude indecision making.The time available to accomplish the obstacle mission is an important consideration.Lead time is required to gain sufficient obstacle density to obtain tangible benefits fromthe obstacle plan. Emplacement time will vary with the types of obstacles. For example,it may take more manhours to emplace a conventional tactical minefield than to emplacea road crater or prepare a bridge for demolition. Emplacement lead time is divided intotwo parts: time required to actually construct the obstacle, and time required to getmaterials to the obstacle location. The latter may require twice as much time as actualobstacle construction. The loss in productivity due to logistics time can be reduced byallocating additional transportation support to engineer units. In most cases, the engineersquad's truck or APC must serve as both personnel carrier (mobility) and cargo carrier(resupply). Another way to increase production is to work maximum hours, but this pacecan be maintained for only a few days before soldiers and equipment begin to fail.Finally, logistical matters must be considered. The commander must set priorities for thedelivery of munitions and material, and must allocate the available haul assets amongammunition, obstacle materials, and other critical supplies. Among obstacle materials,difficult choices must be made. A conventional tactical minefield can take up to ahundred times the haul assets of a point obstacle, yet the minefield may be the onlyeffective obstacle in the situation. To minimize the haul requirements, the engineer mustmake imaginative use of locally available material. Alternative obstacles should also beconsidered. Frequently, tank ditches can be substituted for a minefield, using engineerequipment that is available and not in use, instead of placing an additional demand on anoverloaded transportation system.

7 Determine actual work sequence. The commander and the engineer now mustreconsider the possible obstacles identified earlier. Considering the time available, workforce, and logistical assets, they identify those obstacles which can realistically becompleted within the allotted time. They also identify obstacle work which may continueduring the battle.The commander's obstacle plan will usually develop through the answers to suchquestions as: • Does the unit have 4 hours, 2 days, or 2 weeks before the battle is expected? • What are the limits of obstacle logistic assets available? • Is the divisional engineer unit by itself or is it supplemented by corps engineers? • To what extent is the tactical commander able to augment engineer units with other members of the combined arms team?

8 Determine task organization required. The tactical commander and the engineermust balance the comprehensiveness of the obstacle plan with the realities of limitedassets. For example, a task force commander's sector may be critical and in need ofintensive engineer work in order to complete the plan. The brigade commander, on theother hand, may anticipate that the primary threat will develop in another task forcesector. Accordingly, the brigade commander may allocate fewer engineers than desiredby the task force commander. The engineer recommends the allocation of engineer unitsto best support the brigade commander's coordinated obstacle plan. Additional engineerunits, if available, may be obtained by coordination with the division engineer and thedivision commander. These units may come from the organic engineer battalion or corpsassets.

extensive coordination to accomplish its purpose. The G-4/S-4 must receive a materialsestimate as early as possible in order to plan logistic support of the obstacle system.The artillery fire support coordinator, aviation officer, and air liaison officer must also beconsulted to integrate scatterable mines with the obstacle system. Missions which requirescatterable mines are planned in detail to include the location, the unit delivering themines, and necessary logistic support. Coordination and responsibilities for scatterablemine employment are outlined in chapter 5.Obstacles must also be coordinated with follow-on and adjacent units to insure that thelocation and extent of the obstacle system are known. This coordination will preclude theobstacle impeding movement and maneuver of friendly forces. If followed, this planningsequence is a workable, realistic, and coordinated approach to planning obstacleemployment. It will insure that the result is a coordinated and executable plan thatextracts the greatest cost from the enemy.

OFFENSIVE PLANNING CONSIDERATIONS

In the offense, the priority of the engineer effort is to maintain friendly force mobility.Countermobility activities are also important to halt or slow the enemy's counterattackcapability and isolate the battlefield. Such operations assist friendly forces in defeatingthe enemy in detail. Countermobility operations can be employed in all types of offensiveoperations. Obstacles and mine warfare in offensive operations have three main purposes:1 Prevent enemy enforcement.2 Facilitate economy of force.3 Provide security.

weaknesses. To prevent the enemy from reinforcing weak areas under friendly attack,critical routes should be interdicted to hinder movement of reserves and logistics. Speedand deep interdiction capabilities are vital, Air-delivered scatterable mines are ideallysuited for this mission.

2 Facilitate economy of force. Obstacles and mines can be utilized in selected sectors toallow defense by reduced forces. Relieved maneuver units can then be concentrated inother sectors for the attack. Under other circumstances, easily defended terrain which isreinforced with obstacles and on-call scatterable mines may permit major sectors to beheld by a relatively small force. Operations of this type are conducted by armored cavalryunits with a screen or a protection mission.

3 Provide security. In offensive operations, mines and obstacles may be emplaced alongthe flanks of advancing forces in critical areas to halt or slow enemy counterattacks. Inplanning offensive operations, avenues of approach offering natural flank protection--such as a river or a ridge line--should be carefully evaluated. During the advance, it maybe possible to protect a flank by destroying all bridges crossing a river, or by interdictingall roads and trails crossing a ridge line. Swamps, canals, lakes, forests, and escarpmentsare natural terrain features that can be quickly reinforced for flank security.During offensive operations, engineer countermobility plans must permit rapidemplacement and flexibility. Time and resources will not permit development of theterrain's total defensive potential. Based upon likely enemy reaction, the most probablecounterattack avenues should be closed off with obstacles. Plans should be developed forother possibilities and resources committed when the enemy response becomes apparent.Scatterable mines are excellent for this purpose. Aircraft and artillery deliveredscatterable mines could be preplanned on each of several available routes. The minesshould be delivered in front of, on top of, or on the flanks of the lead elements of anenemy counterattack after the enemy has committed itself to one of the routes. Rapidcratering devices are another excellent capability.Speed of countermobility operations is vital and cannot be overemphasized. Engineersupport must keep up the pace and emplace obstacles and mines along with advancingmaneuver forces. Effort for countermobility during offensive operations must becarefully weighed against the mobility requirements to support the advance. Resourcesmust be planned and used wisely. Under ideal circumstances, plans should be flexible forengineer forces to perform both mobility and countermobility operations as the tacticalbattlefield situation requires.Control of mines and obstacles, and accurate reporting to all units are vital. An obstacleor mine in place will hinder either friendly or enemy maneuver. Positive command andcontrol is necessary to insure that minefield and obstacles are not executed until desired.Once executed, they must be reported by the executing unit through operation channelsand posted to operational and intelligence maps. Information on obstacles and minefieldin place is disseminated with tactical intelligence. The recording and reporting proceduresfor scatterable mines must be rigidly followed. These procedures are discussed in chapter5. Key factors for countermobility activities during offensive operations are: • Enemy situation and capabilities. • A good terrain analysis to determine where friendly forces are vulnerable to counterattack. • Speed of obstacle emplacement. • Preplanning and coordination. • Information flow to inform friendly forces of friendly and enemy obstacle locations.

DEFENSIVE PLANNING CONSIDERATIONS

PURPOSES OF THE DEFENSE

Defensive operations achieve one or more of the following:

• Cause an enemy attack to fail. • Gain time. • Concentrate forces elsewhere. • Wear down enemy forces as a prelude to offensive operations. • Control essential terrain. • Retain tactical, strategic, or political objectives.The immediate purpose of any defense is to cause an enemy attack to fail. The otherreasons listed contribute to purposes beyond the immediate defense.It may be necessary to gain time for reinforcements to arrive or to economize forces inone sector while concentrating forces for attack in another. In either case, a defense or adelay may achieve these purposes.In some cases, a force may be defending because it cannot attack. The defender thentakes advantage of position and superior knowledge of the terrain. Once the enemy hasbeen committed to the defense and weakened by losses, friendly forces maneuver todestroy the enemy with fires or counterattacks. In other cases, portions of a force may berequired to retain key terrain or essential tactical, strategic, or political objectives.In some instances, these must be first seized by airmobile or airborne forces, and thenheld until a larger force can link with the defender. An underlying purpose of alldefensive operations is to create the opportunity to change to the offensive. All activitiesof the defense must contribute to that aim.The defense has been called the stronger form of war because denying success to theenemy is easier than forcing the enemy to do our will. The defender has significantadvantages over the attacker. In most cases, the ground is better known, and the defenderoccupies first and therefore becomes stronger as positions improve and forces mass. Oncethe battle begins, the defender fights from cover against a more exposed enemy, and usesthe terrain to mask movements as forces gather to block and attack the enemy. Finally,the defender can postpone commitment of major forces until the attack has developed,and then strike the extended enemy over carefully selected and prepared terrain withinthe defensive area. The effects of obstacles, airpower, and conventional weapons onexposed troops, and certain aspects of nuclear, chemical, and electronic warfare, alsofavor the defender.Balanced against the defender's advantages, however, is the attacker's single greatestasset--possession of the initiative. The attacker takes advantage of the opportunities toconcentrate first and surprise the defender by chosing ground, direction of approach, andtime of attack. Also, this initial advantage is used to mislead or distract the defender, slowrecognition of the main attack, and delay implementation of countermeasures. Thedefender's ultimate task is to overcome the attacker's initial advantages and quicklyregain the initiative.Napoleon summarized the requirements of defensive campaigns when he said in hisMemoirs: "The whole art of war consists in a well-reasoned and extremely circumspectdefensive, followed by rapid and audacious attack."The key terms of AirLand Battle doctrine--initiative, depth, agility, andsychronization--also outline the requirements for a successful defense at any level.

Initiative

Seize the tactical initiative locally, then generally, as the battle progresses.

Depth

Fight the enemy throughout the depth of its formations to delay and disorganize, and tocreate opportunities for offensive action. The defender must organize forces andresources in depth to gain the time and space required for flexibility and responsivemaneuver.

Agility

Set the terms of battle through flexible use of fire, maneuver, and electronic warfare. Justas the attacker is committed to an action, the defender changes the situation and therebyforces a different countermove. This overloads the enemy's command and control systemand renders his reaction uncoordinated and indecisive. Effective use of agility can lead tothe enemy's piecemeal destruction.

Synchronization

Synchronize all available tools of battle in. well coordinated combat actions. Violentexecution of plans and aggressive exploitation of enemy vulnerabilities can halt theattacking force's momentum.Initially, the defender will be outnumbered. In the early stages of the battle, the defendermust capitalize on the advantage of fighting from stationary, protected positions to haltthe enemy. Deep attack on the enemy, the actions of security forces, and detailed fire andobstacle plans facilitate containment of the attack.Once the attacker has been controlled and the defender has concentrated forces in the areaof the main attack, the defender can then operate against exposed and precisely locatedsegments of the attacking force. Then, by being under the cover of his own field artillery,air defense, and on ground he has reconnoitered and prepared, the defender has theadvantage. Once the attacker has extended into the defended area, he is vulnerable to firesfrom all sides, surprise attacks on flanks and rear, and loss of the initiative.To succeed, the attacker must shatter the defense quickly and maintain a high pace ofoperations to prevent its reconstitution. To defeat the attacker, the defender must protractoperations, keep the tempo slow enough to allow reaction, and, ultimately, isolate anddestroy attacking forces.The attacker cannot be allowed to focus full strength at one time and place on thebattlefield before defensive countermeasures have been prepared. This can beaccomplished through skillful use of terrain and by interdiction of following forcesthrough deep attack. The attacker's ability to sustain the momentum of the attack and setthe pace of battle must be broken. This will occur if it is difficult to employ fire supportassets, reinforce, resupply, and direct attacking echelons.The attacker must be required to divert energies and efforts into nonproductive venturesand to strike at nonexistent targets through deception, operations security, and maneuver.This dissipates strength and uses resources.Karl von Clausewitz characterized the ideal defense as a "shield of blows." At the onset,the defender yields the initiative to the attacker. However, the defender has theadvantages of prepared positioning and better ground knowledge, and uses them to slowthe momentum of the attack and repeatedly strike the enemy. In defeating the attackers'combined arms coordination, strength, and concentration, the defender destroys theattacking force with effective maneuver supported by flexible firepower. It is notnecessary to kill every enemy tank, squad, or combat system, but only to destroy theability to continue fighting.United States Army defensive doctrine is designed to be applicable anywhere in theworld. The form of defense the commander chooses will depend on the mission, nature ofthe enemy, terrain possibilities, and capabilities of available units. The commander mayelect to defend well forward or in considerable depth, if not required to hold a specifiedarea or position. The commander may even choose to preempt the enemy with spoilingattacks if conditions favor such tactics. Depending on the depth available, forces at hand,and the mission, the commander may defend by striking the enemy as it approaches. Thecommander fights the decisive battle within the main battle area, or draws the enemydeep into the area of operations, and then strikes along enemy flanks and rear. All threemethods have been used in the past with decisive results.

DEFENSIVE FRAMEWORK

Corps and divisions fight a unified defensive AirLand Battle within an organizationalframework consisting of five elements:1 The deep battle.2 Covering force.3 Main battle area.4 Rear battle.5 Reserve operations.The deep battle, the covering force battle, and the main battle area (MBA) battle areplanned as complementary actions which support a unified battle plan. The overallcommander delineates areas of interest and influence, the covering force area (CFA), theforward edge of the battle area (FEBA), the rear line of the MBA, and the rear area. Theforward line of own troops (FLOT) is initially defined by elements of the covering force.After contact with the enemy, FLOT generally defines the line of contact throughout thebattle. The commander also establishes an initial ilre support coordination line (FSCL)and any blocking positions, strongpoints, stay-behind forces, or phase lines necessary forexecuting the plan. The commander decides whether to fight a forward defense or adefense in depth. The commander organizes the overall defensive effort on the basis ofthe mission, the nature of the enemy force, the terrain, the troops assigned, and the timeavailable. The commander allocates forces and resources within the elements of theorganizational framework to support the overall scheme.

1 The deep battle. The deep battle component of the AirLand Battle is designed tosupport the commander's basic scheme of maneuver by disrupting enemy forces in depth.Its goal is to create opportunities for offensive action against committed enemy forces bydelaying the arrival of enemy reserves or follow-on forces, or by destroying key enemy,organizations. Surveillance operations are conducted to identify significant enemy forcesin the area of interest while electronic warfare, long-range fire, and maneuver in depth areused to attack enemy forces whose delay or disruption is important to the success of thecommander's plan. In the defense, the deep battle aims to prevent the enemy fromconcentrating overwhelming combat power. Main objectives are the separation anddisruption of attacking echelons, protection of friendly maneuver and degradation of theenemy's fire support, command and control systems, combat and combat service support.Engineer plans in support of the deep battle will resemble the support given any otheroffensive operation. Emphasis will be upon speed for ground forces. First priority ofengineer effort will be mobility of the maneuver force. Countermobility, in terms of flanksecurity and prevention of counterattack, is the second priority for engineers. Obstacleswill, of necessity, be those that can be installed rapidly, such as scatterable mines androad craters. Scatterable mines will be a significant contributor to success of the deepbattle. Targets and delivery means must be carefully chosen.

2 Covering force. The covering force generally has three basic tasks to accomplish: • Gain and maintain contact with attacking enemy forces. • Develop the situation. • Delay or defeat the enemy's leading fighting forces.In the covering force area (CFA), countermobility activities are primarily designed todisorganize enemy movement and enhance friendly fires. The density of obstacles in theCFA will be less than the MBA due to lack of time, depth of the area, and smallernumbers of engaged friendly forces. Siting obstacles will be extremely important.Manpower and equipment-intensive obstacles will not generally be emplaced in the CFA.The commander must make decisions on the amount of limited resources able to becommitted to the CFA. Emplacement of obstacles in the CFA and the MBA will beoccurring at the same time and competing for the same resources.Time is a critical factor to consider in planning the battlefield preparation of the CFA.There will be little time for obstacle employment once the enemy attacks. Scatterablemines and quick demolition point targets, such as prechambered road craters, are ideal foruse in the CFA. Obstacles should assist the covering force commander by accomplishingthe following: • Enable CFA units to fire and maneuver without becoming decisively engaged. • Inflict casualties and force the enemy to deploy repeatedly, thus gaining time for MBA preparation. • Force the enemy to expend breaching and bridging assets that he will need later when encountering the MBA. • Deceive the enemy as to our MBA locations and intentions.The majority of the engineer effort in the CFA will be accomplished by divisional andcorps combat battalions. Selection of the proper command or support relationships willbe critical due to the rapidity of the battle.

3 Main battle area. The main battle area (MBA) is bounded by corps-designatedcoordination points that establish the forward edge of the battle area (FEBA) anddivision-designated rear boundaries of the forward defending brigades. It is anticipatedthat the decisive battle will be fought by the forward committed brigades in this area.Therefore, the bulk of the defending force is deployed in the MBA. They are prepared toconcentrate where necessary to defeat the enemy's main thrust. For control purposes, theMBA is subdivided by division, brigade, and task force boundaries. It contains amultitude of predetermined (and in some cases, prepared) battle positions from which thebattle will be fought. The use of battle positions facilitates control of the combat elementsduring the flow of battle. They allow the commander to concentrate forces in criticalareas with minimal confusion. The use of obstacles in the MBA is the key to gaining timefor the commander to concentrate forces by slowing the enemy rate of advance. Existingobstacles will place certain restrictions on enemy maneuver and speed. To complementthis, reinforcing obstacles are sited to-- • Take advantage of existing obstacles. • Slow and destroy tanks and BMPs. • Hold the target in the firing window of direct fire weapons. • Gain time for the defender. • Disrupt the integrity of the enemy formations. • Channelize the enemy into other areas where we want him to go.Most of the obstacle effort is concentrated in the MBA. In addition to the divisional units,corps combat engineer battalions will be available to work in the MBA. Elements ofcorps combat heavy engineer battalions will be employed in MBA on a task basis.

4 Rear battle. The rear area is organized to provide for efficient combat serviceactivities. Because most combat forces are forward, support elements must be trained andprepared for self-defense. Obstacles in the rear area are usually limited to protectiveminefield and command priority point obstacles. These obstacles will normally beconcentrated in areas that could be used by the enemy as helicopter landing zones or dropzones for airborne forces. Scatterable mines, especially antipersonnel mines, could beused on targets of opportunity in the rear area. The rear battle commander will becompeting with maneuver forces for scarce countermobility resources. The overallcommander will establish priorities for effort and expenditure of materials throughout thedepth of the battlefield.

5 Reserve operations. The reserve force, regardless of size, will require engineersupport in order to accomplish its mission of counterattack, defensive reinforcement, orreaction to a rear area threat. If the reserve force is primarily made up of aviation assets,then the engineer support required will be significantly reduced. Engineers supporting thereserve force can possibly be employed in the MBA with anon-order mission to supportthe reserve force. This method requires timing and mobility if the engineer unit is to joinup and deploy with the reserve force. Engineer forces can also be located with the reserveforce to provide survivability and countermobility support. This insures the unit willremain intact and capable of performing its mission.

RETROGRADE PLANNING CONSIDERATIONS

A retrograde operation is an organized movement toward the rear or away from theenemy. It may be forced or voluntary, but must be approved by the appropriate highercommander. Forces conduct retrograde operations to harass, exhaust, resist, delay, anddamage the enemy. Such operations gain time, avoid combat under unfavorableconditions, or draw the enemy into unfavorable positions. They are also useful inmaneuver to reposition forces, shorten lines of communications, or permit the use of aforce elsewhere.

TYPES OF RETROGRADE OPERATIONS

The three types of retrograde actions are delays, withdrawals, and retirements. Indelays, units give up space to gain time. They do not lose freedom to maneuver, and theyinflict the greatest possible punishment on the enemy. In withdrawals, all or part of adeployed force voluntarily disengages from the enemy to free itself for a new mission.Withdrawals may occur with or without enemy pressure and assistance by other units.In retirements, a force not in contact with the enemy conducts an administrativemovement to the rear.All retrograde operations are difficult, and delays and withdrawals are inherently risky.To succeed, they must be well organized and executed.

DELAYING OPERATIONS

Delaying operations occur when forces are insufficient to attack or defend, and when thedefensive plan calls for drawing the attacker into an unfavorable situation. Theseoperations normally gain time to-- • Reestablish the defense. • Cover a defending or withdrawing unit. • Protect a friendly unit's flank. • Participate in an economy of force effort.Delays gain time by forcing the enemy to concentrate repeatedly against successive battlepositions. As enemy units begin to deploy for the attack, the delaying force withdraws tonew battle positions. The enemy must repeat the same time-consuming deployment at thenext position. At the same time, deep attack slows the enemy's advance and prevents himfrom massing overwhelming combat power against the delaying force. A delaying forcemust-- • Maintain contact with the enemy to avoid being outmaneuvered. • Cause the enemy to plan and conduct successive attacks. • Preserve its freedom to maneuver. • Maintain operational coherence. • Preserve the force.A delaying force can-- • Harass, exhaust, weaken, and delay enemy forces. • Expose or discover enemy weaknesses. • Avoid undesirable combat. • Gain time for the remainder of the force. • Conform to movements of other friendly troops or shorten lines of communications. • Cover the deployment, movement, retirement, or withdrawal of friendly units.Although the delaying force will likely be outnumbered, it must seize the initiativewhenever possible to conceal a weakness or disrupt enemy plans. To provide the requiredtime, units with a delay mission may attack, defend, screen, ambush, raid, or feint. Acommander who is delaying may defend initially and then shift to the delay only after theenemy has concentrated overwhelming combat power against initial positions. Thecommander then gains time by occupying succeeding battle positions and conductingshort counterattacks until space runs out. If space is limited, the commander may have toaccept greater risks to accomplish the mission. A commander's orders may requiredelaying the enemy forward of a certain line until a certain time. To do so, thecommander would have to accept a decisive engagement.Cavalry units train and organize especially for delaying operations. When available, theyshould execute the delay.

Delay from successive positions

Delay from successive positions occurs when the sector is so wide that available forcescannot occupy more than a single tier of positions. Maneuver units continuously delay onand between positions throughout their sectors. This method is simple to control. Delayfrom successive positions is useful in less dangerous sectors, but is easier to penetratethan a delay from alternate positions because the force has less depth and time to prepare. Delay from alternate positions

Delay from alternate positions involves two maneuver units in a single sector. While thefirst is fighting, the second occupies the next position in depth and prepares to assumeresponsibility for the operation. The first force disengages and passes through or aroundthe second force. It then prepares to resume the delay from a position in greater depth,while the second force takes up the fight. Delay from alternate positions is useful inparticularly dangerous avenues. This method offers greater security than delay fromsuccessive positions, but requires more forces, continuous coordination of fire andmanuever, and is less certain to maintain contact with the enemy.

As the enemy's main effort becomes clear, commanders may add forces to threatenedsectors and withdraw them from uncontested areas. But any delay maneuver must be alertfor opportunities to damage the enemy with short, sharp offensive actions. Such actionskeep the enemy on guard and lengthen the delay. Delay Preparations

OrdersThe time available determines the extent of preparations. It is not always possible tocomplete preparations before the delay starts. Consequently, commanders preparecontinuously and adapt plans as situations develop.

The order for the delay outlines the entire operation and describes its initial phase indetail. The commander issues supplementary orders during the battle to adjust andcoordinate the delay. Missions assigned to subordinate elements and their sequence ofexecution are often more restrictive than other types of operations. Sufficient initialguidance will permit a subordinate commander to fight effectively even if contact is lostwith the commander. Each subordinate commander, however, needs enough freedom toexploit any advantage which may develop.PlanningThe delaying force commander usually organizes the operation by identifying delaypositions in depth throughout the area of responsibility. These positions normally follownatural lines of defensible terrain across the sector. Times may be assigned to delaypositions indicating the minimum acceptable delay in each area. Commanders mustcarefully weigh the implied risks when imposing time limits on the delay.Because sectors in a delay are usually wide, commanders must organize maneuver forcesfor independent operations. Every subordinate delaying force commander mustunderstand the tasks and restrictions. Artillery and engineer support will usually beprovided to the battalion or squadron level. Attack helicopter units are also valuablereserves in a delay because they are fast and effective against tanks.The commander plans for offensive action as part of the basic delaying maneuver, andassigns responsibility to specific units for contemplated counterattacks. Unless reservesare prepared to strike, and preliminary plans for air, artillery, and engineer support areready, the delaying force will miss opportunities.

Delay command and control

The dynamic nature of the delay places a premium on the commander's ability to stayabreast of the situation and understand the options as the operation progresses. Eachcommander must be aggressive in obtaining and reporting information. Even duringactive combat, staffs must actively seek information and immediately report essentialinformation to the commander. Division and corps commanders must pass gatheredinformation to the delaying unit.Commanders must know the status and location of their own units, flanking units, andenemy units. To enhance coordination, each commander will use prominent terrainfeatures, redundant communications, rehearsals, simple maneuver schemes, and liaisonparties. Wide frontages and multiple attacks will make it impossible for the commanderto be present at every significant action. The intensity of combat will limit mobility, thecondition of forces, and logistic posture. The obstacle plan must be known well enough tocontrol the operation. Commanders must closely monitor and control radiocommunications during the delay. They should use wire communications betweencommand posts, to reserves, and to delay positions that are particularly important. Theyshould also set up dummy stations to deceive the enemy regarding strength and missions.

Delay execution

Divisions and smaller units delay from successive positions, delay from alternatepositions, or a combination of both. At least a portion of the delaying force maintainsconstant contact with the enemy. Long-range fire, maneuver, and direct fire cause theenemy to deploy, reconnoiter, maneuver, or even halt. Nuclear or chemical fires, andshort, violent counterattacks or ambushes disorganize and inflict casualties on him.Spoiling attacks as the enemy prepares to attack can also substantially delay his advance.Effective use of obstacles will be a key element in executing a successful delay.Regardless of the type delay tactics used, obstacles enable the commander to effectivelytrade space for time. Obstacles which can be rapidly emplaced such as scatterable mines,bridge destruction, and road craters, are ideal to support the delay. Timely and properplacement of obstacles enable a commander to break contact, utilize economy of force,and provide valuable time to forces preparing the primary defensive area. Obstacles alsoweaken the enemy and his use of breaching assets, and cause him to be more vulnerablewhen encountering the main defensive area.Beginning the delayIf no enemy contact occurs, reconnaissance forces will aggressively seek it on a widefront. They will repel enemy reconnaissance forces and determine the direction of enemymovement. At this point the delay begins.A delaying force maintains continuous contact with the enemy, but avoids a decisiveengagement unless the mission demands it. The delaying operation, which requirescareful planning, should resemble a dynamic defense, yet it must be flexible enough toadjust to enemy maneuver. When the enemy discovers he is facing a delay, he willnormally attempt to close and to penetrate. Early intelligence of enemy movementspermits the defense to adjust, and also minimizes enemy success.Maintaining control and coherenceControl and security during a delay derives from planning. The commander must insurecontinued coherence by-- • Using well-planned and coordinated obstacles. • Minimizing gaps between forces. • Maintaining surveillance of gaps. • Insuring that displacing forces occupy intended positions. • Maintaining unit integrity, especially of smaller units. • Properly executing all elements of the obstacle plan. • Insuring that reports are timely and accurate. • Maintaining contact with the enemy. • Continuously and aggressively acquiring intelligence about the area of interest. • Maintaining a reserve.Contesting the initiativeA successful delay requires commanders to take the initiative whenever possible,throwing the enemy off stride and disorganizing him with-- • Timely and effective use of obstacles. • Direct and indirect fires which are violent and coordinated. • Counterattacks and spoiling attacks. • Timely nuclear and chemical fires. • Skillful deception. • Aggressiveness. • Effective offensive air support.Concluding the delayThe delay can be concluded under several conditions, most probably when enemy forceshave halted the attack or when the delaying force has achieved its mission and passedthrough another force. If the attacking force has halted because of attrition or logisticconsiderations, the commander of a delaying force can withdraw for another mission ormaintain contact. The higher commander may choose to attack through a delaying force.In this kind of operation, timing for such an attack is usually critical. To facilitate it, thedelaying force must assist in the forward passage of lines and provide knowledge of theenemy and terrain.Passing lines under pressureIf the delaying force withdraws through a defending force, it must pass through lines tothe rear and hand off the battle to the defending force. The success of the delay's finalstage requires-- • Using obstacles to assist in breaking contact. • Planning routes. • Coordinating passage points. • Recognizing signals. • Exchanging liaison parties. • Supporting with fires.Passage of lines is especially difficult in limited visibility. Transition should thereforeoccur just forward of the new defense in such a way that location and organization are notrevealed.In many instances, it will be preferable to pass delaying units to the rear in sectors notunder direct attack. Commanders may do so by maneuvering delay forces away from theenemy's front just before it reaches the main defense. If the delaying force can lead anaggressive enemy into the defense, it can cause heavy damage.

WITHDRAWAL OPERATIONS

When the commander finds it necessary to reposition all or a part of the force, awithdrawal is conducted. The deployed force voluntarily disengages from the enemy. Theoperation may occur with or without enemy pressure and assistance by other units.Without enemy pressure, withdrawing requires effective security and depends primarilyon speed and deception. Stealth or a nuclear or ground attack may be necessary to divertthe enemy's attention. Commanders must have contingency plans in case the enemydetects the withdrawal and attacks. Successful withdrawals normally occur at night orduring poor visibility conditions. They also occur in difficult terrain under friendly airsuperiority, even though poor visibility and difficult terrain complicate friendly control.Smoke and concealed routes can reduce the enemy's ability to observe friendlymovements, but commanders must anticipate enemy interference by fires and maneuverin depth.Under enemy pressure, withdrawing depends on maneuver, firepower, and control. Allavailable fires, perhaps even nuclear fires, support the withdrawal of closely engagedfriendly forces. Forward elements move to the rear by aggressive small-unit delayingtactics. Rearward movement must be tightly coordinated and controlled.When simultaneous withdrawal is not practicable, the commander must determine anorder of withdrawal. If the most heavily engaged units are withdrawn from the areas ofgreatest enemy pressure first, the enemy may encircle or destroy major elements of thecommand. If the least heavily engaged units are withdrawn first, all or a major portion ofthe most heavily engaged units may be lost. Commanders must decide what action bestpreserves force integrity while accomplishing the mission.

Reserves deploy well forward to assist withdrawing units by fire or ground attack. Whileunits are withdrawing under pressure, reserves can launch spoiling attacks to disorganize,disrupt, and delay the enemy. Reserves may also cover the withdrawal or extricateencircled or heavily engaged forces. Army aviation units secure flanks, delay enemyarmor, maintain command and control, and transport troops and materiel.

RETIREMENT OPERATIONS

A retirement is a rearward movement by a force not in contact with the enemy. It is

administrative in nature and execution, but commanders should have contingency plans ifthere is any chance of a meeting engagement.

EMPLOYMENT OF OBSTACLES IN RETROGRADE OPERATIONS

The use of obstacles in retrograde operations varies widely depending upon the nature ofthe operation. In the delay, planning and executing obstacles is much the same as in thedefense. At the other end of the scale, obstacles will rarely be employed to supportretirements, except for those that are part of denial operations. Obstacle use in thewithdrawal falls between these extremes.Obstacles are used in both the defense and retrograde, but some significant differencesare: • Friendly forces will be even less numerous relative to the attacker, and will be more widely dispersed. With both time and troops to emplace obstacles at a premium, there will be fewer obstacles. Because of this and the greater need for them by friendly forces, each obstacle assumes greater importance. • Extensive obstacle systems will be rare in retrograde operations. Single or small groups of mutually supporting obstacles will be sited at the most critical locations. Obstacles coordinated with antitank fires will be located in depth on likely avenues of approach and along each delay position. • Thorough knowledge of the terrain is even more important in retrograde than in other operations. It is essential to find the most suitable locations for reinforcing obstacles, and to take the greatest advantage of the pattern of existing obstacles because of the severely limited time and effort available.These considerations lead to emphasis upon reinforcing obstacles that can be emplacedand executed rapidly, and offer the greatest delay effect for the preparation effort such asbridge demolitions, point obstacles (including point minefield), and scatterable mines. Inthe delay, obstacles are used primarily to enhance antiarmor direct fire weapons. Theyalso are placed in depth to assist delaying forces in breaking contact.The delay provided by the second set of obstacles is vital if our forces are to succeed inbreaking away to move to the next delay positions. In the withdrawal, obstacles areplaced to slow the enemy's pursuit and disrupt his plans, and also to assist friendly forcesin avoiding decisive engagement.Because the attacker seeks rapidity of movement, he will attempt to use the road net. Thefirst priority for obstacles is to those that block key avenues of approach, especially atmajor choke points (including bridges) and sites suitable for hasty river crossings. Thenext consideration is developing obstacles directly assisting planned withdrawals tosuccessive delay positions, generally along the delay positions.Because uncertainty is a large factor in the retrograde, obstacles that assist in preventingsurprise to the friendly force are important. They give the delay force commander time toshift fires and move reserves to threatened areas. Special attention must be paid toobstacles that cover the flanks, and to lightly-held areas to counter the Threat doctrine ofoutdistancing and enveloping withdrawing forces. Potential airlanding or air drop zonesalso rate special attention in planning obstacles. Because the enemy can readily identifykey choke points from maps, nearby landing or drop zone sites are especially important,and are best covered by planned scatterable mines.In retrograde operations, engineers normally accompany all units. Security forcesnormally have engineers attached. The basic load of obstacle materials carried byengineers will provide a limited capability to create obstacles. In addition, the retrogradefacilitates stockpiling of obstacle materiel to support rapid placement of plannedobstacles.Distributing engineer units throughout the force also places counterobstacle equipmentand facilities where they will be able to immediately breach interdictory obstacles (thosethe attacker might place behind withdrawing forces).To the maximum extent possible, obstacles are sited to enhance the kill probabilities ofantitank weapons. However, if necessary, the general principle that obstacles must becovered by direct fire or observed indirect fire can be relaxed in retrograde operations.Remote electronic sensors or other devices can be used to trigger planned artillery fire ormines, and make breaching very costly if observed fire is not possible.

Obstacle planning

In retrograde operations, obstacle planning must be done in as much detail as time willallow, but execution is closely controlled to assure that the effort is invested where it ismost needed as the situation develops. Scatterable mines are particularly well-suited foruse in retrograde operations because they can be placed where, when, and as needed.Their use is carefully planned to reduce delivery time. Planned sites include choke pointsnot readily closed by demolitions, likely routes of advance, areas suitable for enemyartillery positions, likely landing or drop zones, and river crossing sites. Whereavailability of force permits, selected engineer units can be specially trained, reinforced,and employed under centralized control to emplace obstacles rapidly after the enemy'smain effort is identified, or to respond to sudden changes in the situation.

Reserved demolitions

Common in the retrograde, reserved demolitions must be tightly controlled by the lowestcommander responsible for all units involved in passage of the obstacle. Other criticaldemolitions, such as bridges, should be executed as soon as prepared to preclude thepossibility of capture and the requirement for demolition guards.

Deception

Deception is important in all retrograde operations and critical to withdrawal. Friendly

forces must keep the attacker confused--uncertain of our plans and the location anddisposition of our forces. Obstacles must be so planned that their execution will notinadvertently reveal friendly plans or positions. Concealed obstacles, use of dummyobstacles, and varied, expedient obstacles will assist in deception. Obstacle emplacementwill frequently have to be carried out at night and under cover of smoke.

Denial targets

Denial targets are common in retrograde operations. In addition to those assigned by

higher headquarters, division and brigade will frequently wish to add to their own"tactical" denial targets, such as those designed to destroy the usefulness of the road net.Disabled equipment and supplies, or other materials that cannot be evacuated, will alsohave to be destroyed.

Coordination

Coordinating obstacle planning and preparation takes on the greatest importance in

retrograde operations. Corps or theater army engineer units may be tasked to constructpositions and obstacle systems well to the rear of the forces who will eventually fightthere. In this instance, coordination arrangements between the preparing and final usingunits becomes vital.

SUMMARY

Planning considerationsMission.Directed and reserve obstacles.Future plans.Enemy strengths and weaknesses.Terrain and weather.Available resources.Effects on local population.Obstacles should support weapon systems, not impede future mobility, supportmovement from battle position to battle position, and be placed in depth.Retrograde operationsRetrograde operations include the delay (to trade space for time), the withdrawal (todisengage from enemy contact), and the retirement (to move away without contact).Retrograde operations are planned by corps and division, but may be carried out bybrigade. They feature centralized planning and decentralized execution.Threat forces seek to penetrate, bypass, and cut off friendly forces in the retrograde.The best possible use must be made of existing obstacles; reinforcing obstacles mustoffer the best return for the effort invested.Obstacles priorities are to key choke points, delay positions (with priority to the mostforward delay position), and flanks. Among positions, priority is always to the initialdelay position.In the delay, obstacles assist in inflicting losses and breaking contact. In the withdrawal,obstacles assist in slowing the attacker, disrupting his plans, and avoiding decisiveengagement. In the retirement, obstacles may be planned for security.Scatterable mines are ideal for retrograde use.Careful planning and tight control of reserved demolitions is necessary to precludepremature demolition or capture by the enemy before detonation.Chapter 5

MINE WARFARE

Mines destroy, delay, disrupt, and channel enemy forces. They provide a very effectivemeans of terrain control and casualty infliction on the enemy. Mine warfare systems areflexible. Compared with the costs of other weapon systems, mines are efficient andeffective. However, their success and timely employment are factors of their availabilityand transporation assets to haul them.This chapter discusses the classification and employment of various types of minefieldswhich can be emplaced in the AirLand Battle; command and control of both conventionaland scatterable mines to include employment authority; and the reporting, recording,marking, and warning procedures for conventional and scatterable mines. CLASSIFICATION MINEFIELD EMPLOYMENT MINEFIELD EMPLOYMENT AUTHORITY REPORTING, RECORDING, AND MARKING SUMMARY

CLASSIFICATION

Minefields are classified by the purpose they serve. Types of minefields includeprotective, tactical, point, interdiction, and phony. PROTECTIVE MINEFIELDS

Hasty protective minefields

Hasty protective minefields are used as part of a unit's defensive perimeter. They areusually laid by units using mines (conventional or scatterable) from their basic loads.If conventional mines are used, they are laid on top of the ground in a random pattern. Noantihandling devices will be used. They are employed outside hand grenade range butwithin small arms range. All mines are picked up by the emplacing unit upon leaving thearea, unless enemy pressure prevents mine retrieval.If scatterable mines are used for the purpose of hasty protective mining, the system mostlikely to be used is the Modular Pack Mine System (MOPMS). This system is man-portable and can be employed rapidly. The MOPMS container has both antitank andantipersonnel mines and is placed and aimed in the desired direction. If the unitdetermines that the mines should be employed due to enemy action, the box isexplosively command-detonated and the mines scattered. Once employed, the minescannot be retrieved. If the minefield is not required, the unit simply picks up theunexploded box and moves to a new location.

Deliberate protective minefields

Deliberate protective minefields are used to protect static installations such as depots,airfields, and missile sites. Conventional mines are always used and are emplaced instandard patterns, usually by engineers. The field is always fenced, marked, and coveredby fire. These minefields are usually emplaced for long periods. When these minefieldsare to be removed, engineers clear them.

Point minefields disorganize enemy forces and hinder their use of key areas. Pointminefields are of irregular size and shape, and include all types of antitank andantipersonnel mines, and antihandling devices. They should be used to add to the effectof existing and reinforcing obstacles, or to rapidly block an enemy counterattack along aflank avenue of approach.

INTERDICTION MINEFIELDS

Interdiction minefields are placed on the enemy or in his rear areas to kill, disorganize,disrupt lines of communication and command and control facilities. Interdictionminefields are used to separate enemy forces and delay or destroy enemy follow-onechelons. Interdiction minefields are emplaced using air or fire support deliveredscatterable mines.

PHONY MINEFIELDS

Phony minefields, used to degrade enemy mobility and preserve our own, are areas ofground used to simulate live minefields and deceive the enemy. They are used when lackof time, personnel, or material prevents employment of actual mines. Phony minefieldcan supplement or extend live minefields, and may be used as gaps in live minefields. Tobe effective, a phony minefield must look like a live minefield by either burying metallicobjects or making the ground look as though objects are buried. Phony minefields are ofno value until the enemy has become sensitive to mine warfare.

MINE DELIVERY METHODS

The table below (Mine delivery methods and characteristics) relates mines to theirmethods of delivery, self-destruct features, and emplacement characteristics. It alsoidentifies those mines which may or may not be placed in a classical pattern. This tableprovides a basis by which mines can be categorized as scatterable or conventionalaccording to their self-destruct feature. The table below (Mine categories andcharacteristics) lists mines by category, and also provides additional characteristics ofeach mine. MINEFIELD EMPLOYMENT

Mines are a significant combat weapon. Minefields are the most effective means ofreinforcing the terrain to stop, slow, or channelize the enemy into areas where he can bekilled. Minefields can and should be emplaced wherever and whenever the tacticalsituation dictates. The commander's flexibility in minefield employment has beenexpanded extensively with the fielding of multiple mine delivery systems. We can expectboth conventional and scatterable minefields to be the principal countermobility asset.Conventional and scatterable minefields should be employed using the terrain analysisand obstacle planning sequence previously outlined. Conventional and scatterableminefield locations should be preplanned prior to the beginning of the battle, andemplaced when the tactical situation requires.Mine warfare operations must complement the commander's plan for defense, avoidimpeding friendly mobility, and facilitate future operations. The engineer is thecommander's principal advisor in insuring that these objectives are met. To achievesuccess in mine warfare, both the commander and the engineer must carefully controlmine employment. Commanders and staffs throughout the force must know and followauthorizations and requirements to emplace mines and report, record, mark, andcoordinate minefields.Detailed and integrated staff coordination is necessary to develop plans for mine warfareoperations. Coordination begins with the development of a recommended obstacle plan tosupport the commander's scheme of maneuver and plan for fire support. Minefield areincorporated into the obstacle plan as necessary.Preplanned conventional and scatterable minefields will be part of the obstacle plandeveloped for the commander by the engineer. The operations officer, fire supportcoordinator, aviation officer, and air liaison officer (ALO) will assist the engineer.Preplanning will consist of identifying areas for minefields to respond to possible enemycourses of action. Preplanning will facilitate rapid emplacement, especially for minesdelivered by artillery, helicopter, and high-performance aircraft. In all cases, execution isa command decision of the responsible maneuver commander, who must select thedelivery system that best fits the tactical situation and presents the least risk to friendlytroops. Employment will be coordinated with higher, lower, and adjacent units prior toexecution, and reported and recorded afterwards.Conventional minefields will normally be emplaced prior to the beginning of hostilitiesdue to the exposure of manpower and equipment, and due to the length of time necessaryto emplace them. Once the battle begins, conventional minefields could still be emplacedbut would have to be emplaced out of direct fire and, preferably, indirect fire range.Restriction to friendly maneuver or a rapidly changing battlefield is another veryimportant factor to consider. Conventional minefields would rarely, if ever, be emplacedforward of the forward line of own troops (FLOT).Scatterable minefields can and should be planned and emplaced throughout the battle-field as the tactical situation requires and assets allow. Some scatterable systems arebetter suited for specific areas of the battlefield than others. Ground scattering systemsare best utilized for emplacing larger tactical minefields and rapid, small, point, or hastyminefields. These type minefields are usually emplaced in friendly controlled territory.Other scatterable systems such as Artillery, Gator, M56, and Volcano can be employedthroughout the battlefield. Emplacing helicopter delivered mines in enemy territory doesinvolve a great degree of risk to the aircraft and crew. Artillery and high-performanceaircraft delivery systems can be employed anywhere, but are ideally suited to delivermines into enemy controlled areas.Employment of minefields must be carefully planned and emplaced in areas where thecost to the enemy would be greatest. The engineer must recommend, and the tacticalcommander must select, the type minefield and delivery system to accomplish that task.In recent wars, mines have accounted for a substantial portion of equipment andpersonnel losses. Current and future developments in mines and mine delivery systemsare extensive, insuring that mines will be one of the most formidable assets on thebattlefield. MINEFIELD EMPLOYMENT AUTHORITY

LEVELS OF AUTHORITY

The restrictions that minefields impose on friendly mobility, as well as enemy mobility,dictate the need for positive and effective command and control of mine employment.The echelon of command vested with the authority to emplace mines varies with thepurpose of the minefield and type of mines (conventional or scatterable). Minefields thatrestrict maneuver to a greater degree require a higher echelon of authority. In all cases,the responsible commander must insure that the proposed field is coordinated withadjacent, higher, and subordinate units. The commander must further insure thatlimitations to friendly maneuver are minimized, and that all requirements for reporting,recording, and marking are met. Commanders may delegate approval authority to lowerechelons as stated. Also, any higher echelon may retain emplacement authority fromsubordinate elements.At the outset, the corps commander is the employment authority for all scatterable mines.There are many possible combinations of available options depending on the tacticalsituation and future plans. Some example options are: • The corps commander can delegate authority for short self-destruct mines to division commanders, and authorize them to delegate further. However, authority for long self-destruct mines may be retained at corps level. • The corps commander can delegate authority to employ but designate mine-free areas or zones.The general guidance to be followed is the longer the self-destruct time of the mine, thehigher the employment authority should be retained. This criteria will prevent mineemployment from hampering future friendly offensive operations.

AREAS OF INFLUENCE AND INTEREST

The authority level is based upon the type minefield, likely employment location, andimpact on friendly maneuver. The areas of influence and interest for the tacticalcommander also provide a general reference for employment authority for scatterablemines.

Area of influence

The area of influence is an assigned area of operations wherein a commander is capable

of acquiring and fighting enemy units with assets organic to or supporting the command.It is a geographical area, the size of which depends upon the factors of METT-T. It isassigned by higher headquarters and designated by boundaries. Area of interest

The area of interest extends beyond the area of influence. It includes territory whichcontains enemy forces capable of affecting future operations. The area of interest isusually within the next higher headquarter's, and a portion of adjacent unit's, area ofinfluence. DELIVERY RESOURCES

Allocation of delivery resources provides an additional control for the employment

authority. The means of delivery are related to the authority to employ. Before delegatingauthority, the commanders must consider their subordinate's concept of operation.Delivery systems available should be prioritized in allocation similar to other criticalresources.

REPORTING, RECORDING, AND MARKING

Once emplaced, minefields are lethal and unable to distinguish between friend andenemy. For this reason, positive control and a continuous flow of information isnecessary. Reporting, recording, and marking of minefields must be performed usingmethods that are consistent and well understood. The basic differences betweenconventional and scatterable mines require that they be treated differently with respect toreporting, recording, and marking. CONVENTIONAL MINEFIELD REPORTING

A minefield report is an oral, electronic, or written communication concerning mining

activities, friendly or enemy. These reports document information on friendly and enemyminefields. The information is transmitted through operation channels and furnished tointelligence staff officers. It is then processed, integrated with terrain intelligence, anddisseminated through intelligence channels to affected units. Mandatory conventionalminefield reports are: • Report of Intention. • Report of Initiation. • Report of Completion.These reports will be submitted by the emplacing unit commander through operationalchannels to the operations officer (G-3/S-3) of the authorizing headquarters. Thatheadquarters will integrate the reports with terrain intelligence and disseminate themthrough tactical intelligence. The reports should be sent by secure means.

Report of Intention

The Report of Intention is made as soon as it is decided to lay the minefield. It doubles asa request when initiated at levels below those with authority to emplace. This report,when required, includes the following required data (Standardization Agreement(STANAG) 2036) on the proposed minefield: • Tactical purpose. • Type of minefield. • Estimated number and types of mines. • Whether mines are surface laid or buried. • Whether antihandling devices are used. • Location of minefield. • Location and width of lanes and gaps. • Proposed date and time for starting and completing.Conventional minefields which are part of an operation or general defense plan that hasbeen approved by the authorizing commander do not require a Report of Intention. Theirinclusion in such a plan implies an intention to lay.

Report of Initiation

The Report of Initiation is a mandatory report made by the laying unit when installationbegins. It informs higher head-quarters that emplacement has begun and the area is nolonger safe for friendly movement and maneuver.

Report of Completion

The Report of Completion is usually an oral report to the authorizing commander that theminefield is complete and functional. The Report of Completion is followed as rapidly aspossible by the completed DA Form 1355 (Minefield Record) or DA Form 1355-1-R(Hasty Protective Minefield Record). Completion of the minefield records is theresponsibility of the laying unit.

Additional reports

Additional reports may be required by the authorizing commander.

Progress ReportDuring the emplacing process, the commander may require periodic reports on theamount of work completed.Report of TransferThis is a written report which transfers the responsibility for a minefield from onecommander to another. This report must be signed by both the relieved and relievingcommanders. It must include a certificate stating that the relieving commander has beenshown on the ground--or otherwise informed of--all mines within the zone ofresponsibility. It must state that the relieving commander assumes full responsibility forthose mines. The Report of Transfer is sent to the next higher commander who hasauthority over both relieved and relieving commanders.Report of ChangeThis report is made immediately to the next higher commander when the minefield isaltered. It is sent through channels to the headquarters that keeps the written mine record.A Report of Change is made as soon as changes in any of our minefields occur. It is madeby the commander responsible for surveillance and maintenance of the minefield.

CONVENTIONAL MINEFIELD RECORDING

All conventional minefields are recorded on DA Form 1355 (Minefield Record), exceptfor hasty protective minefields, which are recorded on DA Form 1355-1-R (HastyProtective Minefield Record).

Procedures

Preparing the standard minefield record form is the responsibility of the laying unit. Theofficer in charge of the laying must sign and forward it to the next higher command assoon as possible. Once the information is entered, the form is classified SECRET orNATO SECRET, as required. The number of copies prepared depends on the type ofminefield and local procedures. Unit standing operating procedures (SOPs) shouldprovide for information on minefields being passed to higher and lower command levels,and laterally to adjacent units. When the record is made, it should be reproduced at thelowest level having the necessary equipment to make copies. Minefield records arecirculated on a "need to know" basis. When used for training, they are markedSPECIMEN. Large minefield are recorded on two or more DA Forms 1355. Changes

Whenever any changes are made to an existing minefield, a completely new record mustbe prepared on DA Form 1355. This record is marked REVISED and shows theminefield as it is after the changes. The original minefield number remains unchanged.Some changes which require a new record are: • Relocation of mines in safe lanes. • Relocation of safe lanes. • Changed lane or minefield markings. • Inclusion of the minefield into a larger minefield system. • Removal or detonation of mines. • Addition of mines to the minefield.

Methods of recording

OverlayAn overlay should be used when the minefield is to be related to operational maps.Standard military symbols are used in preparing mine warfare overlays.Aerial photographsMinefields can be recorded by aerial photographs if strip centerline tapes are kept inplace until the camera work is done and prominent terrain points can be located. Aerialphotographs can be used in conjunction with DA Form 1355 and attached to thecompleted form.Measuring azimuthAny type of angle-measuring device that can be oriented in reference to magnetic Northcan be used to lay out or plot mines.Conventional minefield records are forwarded through operational channels to theaterArmy Headquarters where they will be maintained on file by the theater engineer.Minefield records may be maintained on file with the Assistant Corps Engineer in whosearea of operation the minefield is located, if deemed necessary.

CONVENTIONAL MINEFIELD MARKING

(STANAG) 2889 is the authoritative reference for marking conventional minefieldsemplaced by NATO forces. Normally, protective and tactical minefields will be fenced toprotect friendly troops, noncombatants, and domestic livestock. In rear areas, minefieldswill be fenced on all sides. Two-strand barbed wire or concertina fences with signs areminimum protection. The Hand Emplaced Minefield Marking Set (HEMMS) may also beused as a marking means. Lanes will be marked using standard minefield marking sets. Inforward areas, minefields will normally be marked only on the friendly (rear) side, or onthe friendly side and the flanks. Lanes will be marked inconspicuously using wire, tape,rope, or easily identifiable terrain features. Minefield markings may be removed uponwithdrawal. Point and interdiction minefield are not normally marked.

Shown below is a synopsis of conventional minefield reporting, recording, and marking

procedures. SCATTERABLE MINEFIELD REPORTING AND RECORDING

Accurate, timely, and uniform reporting and dissemination of scatterable minefield

emplacement information is a must. Fluid and fast moving tactical situations require thatcomplete information on scatterable mine employment be known and passed on in asimple and rapid manner to all units that could be affected. The variety of emplacingsystems and emplacing units precludes the use of locally devised reporting anddissemination methods. Scatterable minefields must also be recorded to facilitate clearingoperations after the war is over. They need not be recorded in the detail required whenemplacing conventional mines. Since the locations of individual scatterable mines areunknown, they cannot and need not be plotted as are conventional mines. The aim pointsor corner points and the type mines emplaced is basic information which must remain onfile for future reference and use.Shown in the illustrations below is a relatively simple reporting and recording procedurethat will be used for scatterable mines. It is applicable for all delivery systems and can besent in a voice, digital, or hard copy mode. This procedure is based upon the varioustypes of emplacing systems. Some systems such as Artillery, Gator, and MOPMS arepoint oriented with the safety zone calculated from one or more aim points. Othersystems such as GEMSS and the M56 have distinct minefield corner points which mustbe reported. The basic purpose of this procedure is to provide one method that is uniformwith all basic information required to report and maintain a record of scatterable mineemployment. This procedure also contains all the information necessary to warn unitswhich may be affected. Warning information can easily be extracted and disseminated tounits which require it.The unit emplacing the mines will immediately report the pertinent information requiredby the most expeditious secure means. If the initial report is not a hard copy report, theemplacing unit will prepare the report in hard copy as soon as possible. The report is sentthrough operations channels to the headquarters authorizing the minefield. Theinformation is posted on operations maps and disseminated to units that are affected. Thereport is then forwarded in the same manner as the conventional minefield record to thesenior engineer in the theater for permanent retention. Forwarding the hard copy report tothe theater commander is not time sensitive. Reports can be batched and forwarded whentime permits. SCATTERABLE MINEFIELD WARNING (SCATMINWARN)

Units which may be affected by the emplacement of scatterable mines will need toreceive a warning to alert them. This warning message may be disseminated prior to orafter the mines are emplaced. Only the very basic information should be included toprevent tie up of communication systems. The following procedure is a convenient andeasily sent message which provides all the necessary information.

responsibilities vary according to the type emplacement system. Listed in the tablesbelow are the basic responsibilities of key command, staff, and units in the planning andemployment of scatterable mines. These responsibilities and actions are based upon thesystem emplacing the minefield. SCATTERABLE MINEFIELD MARKING

The capability of remotely and rapidly emplacing scatterable minefields throughout thebattlefield presents a real problem with regard to marking. Scatterable minefield markingmay be unnecessary or impossible in many cases. Scatterable mines emplaced in enemyterritory are a prime example.Scatterable minefields must be marked to the extent necessary to protect friendly troops.Those emplaced in friendly territory should be marked according to standard markingprocedures. Those emplaced in forward areas are marked on the friendly side and theflank. Minefields emplaced in rear areas are marked on all sides.There is not a specific marking system available for marking scatterable minefields. Thestandard marking procedure described earlier in this section can be used for somescatterable systems such as the GEMSS and M56 which have specific and known limits.Other systems have less definable limits and normally will not be marked due to theiremployment in enemy territory.

ENEMY MINEFIELD REPORTING AND RECORDING

Any detection, encounter, or knowledge of enemy minefields or mining activities must be

reported by the fastest reliable means. The report is made to the next higher commander,and must include all known information about the minefield. The report is normally madethrough operations channels. Specific information and format of that information isoutlined in STANAG 2096 and is as follows. SUMMARY

Conventional minefield key points

Minefields are classified as:Protective.Tactical.Point.Interdiction.Phony.There are three mandatory minefield reports:Report of Intention to lay.Report of Initiation of laying.Report of Completion of laying.There are two minefield record forms:DA Form 1355 (Minefield Record).DA Form 1355-1-R (Hasty Protective Minefield Record).Minefield sites are chosen with the primary purpose of blocking, channeling, and killingthe enemy.Lanes and gaps in minefields are used for the safety of our own troops. Minefield plansmust be coordinated with adjacent units and plans for patrols, supporting fires,counterattacks, withdrawals, and logistic support.Scatterable minefield key pointsEstablish employment authority in the operations order.Plan potential scatterable mine locations early.Emplace scatterable mines based upon enemy disposition and friendly mobility plan.Report scatterable mine locations rapidly.Disseminate information to affected units.Chapter 6

OBSTACLES OTHER THAN MINEFIELDS

There are many countermobility assets and methods at the commander's disposal. Thischapter describes the employment and execution of countermobility activities other thanminefields. Employing all types of obstacles will provide flexibility to the commanderand increase the variety of obstacles that the enemy must encounter. BRIDGE DEMOLITIONS NON-NUCLEAR CRATERS ANTITANK DITCHES EXPEDIENT OBSTACLES PRECONSTRUCTED OBSTACLES ATOMIC DEMOLITION MUNITIONS SUMMARY

BRIDGE DEMOLITIONS

Streams and rivers are formidable obstacles to mobility. In most developed countries ofthe world, bridges have been constructed to span these waterways along lines ofcommunication. Generally, roads and railroads also follow what would be likely militaryavenues of approach. The use of existing bridges is critical to the mobility of a militaryforce. Without existing bridges, forces must conduct river crossings using tacticalbridging. A river crossing operation is one of the most difficult operations to performsuccessfully as it normally requires extensive time and resources.By demolishing or rendering existing bridges unserviceable, we can force the enemy touse time and resources to conduct tactical river crossings. The vulnerability of the enemyis greatly increased during river crossings and presents a good opportunity to destroy hisforces.Bridge destruction cannot be accomplished haphazardly. There are several very importantfactors that must be considered and planned such as: • Extent of destruction. • When to demolish. • Coordination. • Resources. • Effects on local population.

EXTENT OF DESTRUCTION

Only that portion of the bridge essential to accomplish the military objective should bedestroyed. In some instances where the span is short or the bridge has no intermediatesupports, destruction of the entire bridge may be required. In other instances where thebridge is large, dropping a single span may prevent enemy use, conserve demolitions, andmake the bridge easier to reconstruct at a later date. Enemy capability must be a primeconsideration in making this decision.

WHEN TO DEMOLISH

The answer to this question is tactically dependent. Had the Germans blown the Remagenbridge several days earlier, many of their problems would not have occurred. (Seechapter 3.) At the same time, they may have isolated some of their forces on the far bank.If a bridge is blown too early, it may give the enemy time to change direction andtherefore not impede his mobility at all. Waiting too long may enable the enemy tocapture the bridge intact. The commander must make this tough decision only afterconsidering the factors involved.

COORDINATION

The location of friendly forces and future plans of the command are prime factors.Coordination is required with higher, lower, and adjacent units, as well as other servicesin many cases. A worst case example would be for air assets to prematurely destroy abridge that would be a major avenue of approach for a ground counterattack.

RESOURCES

Major bridge destruction requires substantial amounts of time, personnel, and explosives.Planning and coordinating must occur early to insure that resources are available andtargets are executed at the proper time. EFFECTS ON THE LOCAL POPULATION

Unnecessary destruction of bridges has a major impact upon the local population. As withany other denial target, care should be taken to minimize that impact.

NON-NUCLEAR CRATERS

Craters are effective obstacles to enemy movement when constructed properly andlocated at critical points along his movement route. Craters are normally placed on roadsor other high speed movement routes the enemy is expected to use. They should beplaced at locations that cannot be easily bypassed such as cuts or fills. The basic purposesare to delay or stop the enemy, cause his forces to bunch up and provide good targets, andforce him to use up breaching assets such as bridging and earthmoving equipment. Use ofantipersonnel and antitank mines in conjunction with craters creates formidable obstacles.

PLACING

Craters should be placed in depth to prevent the enemy from conducting a single breachand continuing on. There are essentially two placement methods:1 Place craters adjacent to each other.2 Place craters 100 to 1,000 meters apart.

1 Place craters adjacent to each other. This method makes the obstacle extremelydifficult to breach by earthmoving equipment and by a tracked-vehicle launched bridge.The loose soil will cause the bridge to rest unevenly, and exiting vehicles will have noplace to go except into an adjoining crater. When using this method, care must be takenduring the demolition process so that soil blown from one crater does not come to rest inadjacent craters and thus reduce their obstacle value.

2 Place craters 100 to 1,000 meters apart. This method forces the enemy to conductseveral breaches. The factors of METT-T will determine the best crater design andlocation. In any case, craters should be tied into existing or reinforcing obstacles andcovered by direct fire weapons.

DESIGNING

To be effective obstacles, craters must be too wide to be spanned by tracked vehicles, andtoo deep and steep-sided for any other vehicle to pass through them. Blasted road craterswill not stop modern tanks indefinitely, because repeated attempts by the tank to traversethe crater will pull loose soil from the slopes of the crater into the bottom, reducing bothcrater depth and slope angles. Road craters must be large enough to tie into natural orman-made obstacles at each end. The effectiveness of craters may be improved byplacing log hurdles on either side, digging the face nearly vertical on the friendly side,and mining the site with antitank and antipersonnel mines. Wire placed in the crater willadd to the difficulty of mine clearing. BLOWING

There are two common methods of blowing craters:

1 Conventional method, using boreholes loaded with explosives.2 The M180 Demolition Cratering Kit.All military explosives may be used for blasting antitank craters. A special 40-poundcratering charge (ammonium nitrate) issued in a waterproof metal container isspecifically designed for blowing craters and, if available, should be used with theconventional method. The M180 kit comes complete with explosive.

CALCULATING

Hasty road crater

A hasty road crater is emplaced when time and explosives are limited. It is not aseffective as the deliberate crater, which will be described later. The hasty crateringmethod produces a crater 6 to 7 feet deep, and 20 to 25 feet wide with side slopes of 25 to35 degrees. In forming a hasty road crater, all boreholes must beat least 5 feet deep, eachloaded with at least 50 pounds of explosive. Following are the steps necessary to blow ahasty crater.Step 1: Calculate the number of boreholes necessary. Use the formula:

Step 2: Space the boreholes 5 feet apart starting at the center of the roadway andextending in each direction of the desired crater.Step 3: Dig all boreholes to the same depth (at least 5 feet).Step 4: Load each borehole with 50 pounds of explosive.Step 5: Dual prime all charges with detonating cord and connect them to firesimultaneously.Step 6: Stem or backfill all boreholes with suitable material (soil or sandbags).Step 7: Blow the crater. Deliberate road crater

This cratering method produces road craters which are more effective than those resultingfrom the hasty method but require more time and explosive. The deliberate methodproduces a deeper (7 to 8 feet), wider (25 feet), and steeper-sided (30 to 37 degrees)crater than the hasty method. The calculations for a deliberate crater are the same as ahasty crater with the following exceptions: • End holes are 7 feet deep and contain 80 pounds of explosive. • Each alternate hole is 5 feet deep and contains 40 pounds of explosive. • Do not place 5-foot holes next to each other. Relieved face road crater

This cratering method produces road craters that are more effective obstacles to moderntanks than the hasty or deliberate method, but they require still more time and explosivethan the hasty or deliberate. This technique produces a trapezoidal-shaped crater about 7feet deep and 25 to 30 feet wide with unequal side slopes. In compact soil such as clay,the relieved face cratering method will provide an obstacle shaped as shown in the topview, below. The side nearest the enemy slopes at about 25 degrees from the road surfaceto the bottom, while that on the opposite or friendly side is about 30 to 40 degrees steep.The exact shape, however, depends on the type of soil found in the area of operations.The procedure is as follows:Step 1: On dirt or gravel-surfaced roads, drill or blast two rows of boreholes 8 feet apart,spacing the boreholes on 7-foot centers. On hard-surfaced roads, drill the two rows 12feet apart. The number of charges for the friendly side row can be calculated by theformula:

Any fractional number of holes should be rounded UP to the next highest number.Stagger the boreholes in the row on the enemy side in relationship to the other row, asshown in the sideview, below. The enemy side row will always contain one less boreholethan the row on the friendly side.Step 2: Make the boreholes on the friendly side 5 feet deep and load with 40 pounds ofexplosive; on the enemy side, 4 feet deep and load with 30 pounds of explosive.Step 3: Prime the charges in each row separately for simultaneous detonation. Thereshould be a detonation delay of ½ to 1½ seconds between rows, the row on the enemyside being detonated first. Best results will be obtained if the charges on the friendly sideare fired while the earth moved in the first row is still in the air. Standard delay caps maybe used for delay detonation.Step 4: If adequate means for sufficient time for delay firing are not available, acceptableresults may be obtained by firing both rows simultaneously. However, the resulting craterwill not have the same depth and trapezoidal shape as previously described.Step 5: To prevent misfires from the shock and blast of the row of charges on the enemyside (detonated first), the detonating cord mains and branch lines of the row on thefriendly side (detonated last) must be protected by a covering of about 6 inches of earth.

Angled road crater

This method is useful against tanks traveling in defiles or road cuts where they mustapproach the crater straightway. The road crater is blasted using either the hasty ordeliberate cratering methods, except the boreholes are drilled across the roadway at abouta 45-degree angle as shown. Because of the angle tanks must attempt to cross, they tendto slip sideways and ride off their tracks. MAKING BOREHOLES

Boreholes for cratering charges may be dug by using motorized post hole augers orhandheld post hole augers or diggers, or blasted using shaped charges. Making theboreholes is normally the most time-consuming task related to cratering. Breaching hard-surfaced pavementsHard-surfaced pavement of roads and airfields is breached so that holes may be dug forcratering charges. This is done effectively by exploding tamped charges on the pavementsurface. A 1-pound charge of explosive is used for each 2 inches of pavement thickness.The charge is tamped with material twice as thick as the pavement. Boreholes which havebeen drilled or blasted through pavement and contain placed charges can also breachpavement. (A shaped charge readily blasts a small diameter borehole through thepavement and into the subgrade.) Concrete should not be breached at an expansion jointbecause the concrete will shatter irregularly. Blasting with shaped chargesStandard shaped charges may be used to blast boreholes in both paved and unpavedsurfaces for rapid road cratering with explosives. The 15-pound M2A4 shaped charge,detonated at 3 ½ foot-standoff, and the 40-pound M3A1 shaped charge, detonated at 5-foot standoff; will blast boreholes of depths up to 9 feet with diameters 7 inches andlarger in both reinforced concrete pavements and gravel-surfaced roads. For maximumeffectiveness, M3A1 shaped charges should be used to blast boreholes in thick,reinforced concrete pavements laid on dense highstrength base courses. The M2A4shaped charges may be used effectively to blast cratering charge boreholes in reinforcedconcrete pavement of less than 6-inch thickness laid on thin base courses, or to blastboreholes in unpaved roads. Almost all types of military explosive, including thecratering charges, can be loaded directly into boreholes made by the M3A1 and M2A4shaped charges. Shaped charges do not always produce open boreholes capable of beingloaded directly with 7-inch diameter cratering charges without removing some earth orwidening narrow areas. Many boreholes having narrow diameters but great depth can bewidened simply by knocking material from the constricted areas with a pole or rod, or bybreaking off the shattered surface concrete with a pick or crowbar. For road cratering onasphalt or concrete-surfaced roadways, blasting the boreholes with shaped charges willexpedite the cratering task by eliminating the requirement for first breaching thepavement with explosive charges.

Blasting in permafrost

A good rule of thumb is to increase by one-and-one-half to two times the number of

boreholes and charges from those calculated by standard formulas for moderate climates.Frozen soil, when blasted, breaks into large clods 12 to 18 inches thick and 6 to 8 feet indiameter. As the charge has insufficient force to blow these clods clear of the hole, theywill fall back into it when the blast subsides. Testing should be made to determine thenumber of boreholes needed before extensive blasting is attempted. In some cases,permafrost may be as difficult to blast as solid rock.Using standard drill equipment has one serious defect--the air holes in the drill bits freezeand there is no known method of avoidance. Steam point drilling is satisfactory in sand,silt or clay, but not in gravel. Charges must be placed immediately upon withdrawal ofthe steam point, otherwise the area around the hole thaws and plugs it. Shaped chargesalso are satisfactory for producing boreholes, especially for cratering. A low velocityexplosive like ammonium nitrate should be used if available. The heaving quality of lowvelocity explosives will aid in clearing the hole of large boulders. If only high velocityexplosives are available, charges should be tamped with water and permitted to freeze.Unless high velocity explosives are thoroughly tamped, they tend to blow out of theborehole.

Blasting ice

Access holesAccess holes are used for water supply and to determine ice thickness in computing safebearing pressures for aircraft and vehicles. As ice carries much winter traffic, its bearingcapacity must be rapidly ascertained when forward movements are required. Smalldiameter access holes are made by shaped charges. On solid lake ice, the M2A4penetrates 7 feet and the M3A1, 12 feet. These charges will penetrate farther, but thepenetration distances were only tested in ice approximately 12 feet thick. If the regularstandoff is used, a large crater forms at the top which makes considerable probingnecessary to find the borehole. If a standoff of 42 inches or more is used with M2A4shaped charge, a clean hole without a top crater is formed. Holes made by the M2A4average 3½ inches in diameter, while those made by the M3A1 average 6 inches.Ice conditionsIn the late winter, ice grows weaker and changes color from blue to white due to aging.Although ice structure varies and its strength depends on age, air temperature, andconditions of the original formation, the same size and type of crater is formed regardlessof the standoff distance. If the lake or river is not frozen to the bottom and there is a footor more water under the ice, the water will rise to within 6 inches of the top after the holeis blown, carrying shattered ice particles with it. This makes the hole easy to clean. If thelake is frozen to the bottom, the blown hole will fill with shattered ice and clearing willbe extremely difficult. Under some conditions, shaped charges may penetrate to a depthmuch less than that indicated in the table below.Surface chargesSurface craters may be made with ammonium nitrate cratering charges or demolitionblocks. For the best effects, the charges are placed on the surface of cleared ice andtamped on top with snow. The tendency of ice to shatter more readily than soil should beconsidered when charges are computed.Underwater chargesCharges are placed underwater by first making boreholes in the ice with shaped charges,and then placing the charge below the ice. An 80-pound charge of M3 demolition blocksunder ice 4 ½ feet thick forms a crater 40 feet in diameter. This crater, however, is filledwith floating ice particles and, at temperatures around 20 degrees Fahrenheit (F), freezesover in 40 minutes.A vehicle obstacle may be cratered in ice by sinking boreholes 9 feet apart in staggeredrows. Charges (tetrytol or plastic) are suspended about 2 feet below the bottom of the iceby means of cord with sticks bridging the tops of the holes. The size of the chargedepends upon the thickness of the ice. An obstacle like this may retard or halt enemyvehicles for approximately 24 hours at temperatures around -24 degrees F.

THE M180 DEMOLITION CRATERING KIT

The M180 demolition cratering kit is specially designed to produce craters in all types ofsoil and road surfaces, to include reinforced concrete. The kit is self-contained andconsists of a shaped charge, a firing device, a 40-pound cratering charge, rocket motor,tripod, and demolition circuit. The M180 can create craters much more rapidly thanmethods previously described. The M180 can be employed in various configurationsdependent upon the width of the desired crater. The figure below shows how to determinethe number of kits necessary to crater roads of varying widths, and proper spacing andalignment. The M180 can be erected and fired within 20 minutes of arrival on site by twosoldiers. It requires no site preparation. ANTITANK DITCHES

Tank ditches are one way to degrade an attacking force's speed and mobility. Theyimpede the advance by slowing vehicles and confusing the crews. Well-planned tankditches have the advantages shown and described. EMPLOYMENT

Tank ditches should complement existing obstacles to include:

• Slopes greater than 35 degrees. • Steps over 1.5 meters high. • Ravines, gullies, and ditches wider than 3 meters. • Swamps and marshes over 1 meter deep. • Forests having trees over 8 inches in diameter. • Forests having 15 degree slopes and trees over 4 inches in diameter. • Built-up areas.Construction of antitank ditches is time and equipment intensive. Maximum use shouldbe made of the terrain. Also, the shortest antitank ditch or ditch system possible should beused.A tank ditch alone is not an adequate obstacle and will not stop a determined attacker.Additional procedures to increase ditch effectiveness are to-- • Locate the tank ditch within the maximum effective range of antitank weapons from covered and concealed firing positions. • Preplan artillery and air strikes in antitank ditch areas. Artillery and air strikes force the enemy to button up while attempting to breach the ditch, making him more vulnerable to direct fire weapons. • Emplace antitank mines on both friendly and enemy sides of the ditch, especially in the loose soil material and the ditch bottom, to multiply effectiveness. Even the smallest ditch will strip mine plows and rollers from the front of the attacking force, thus making the enemy more vulnerable to mines on the friendly side of the tank ditch. • Place concertina wire, water, or antipersonnel mines in the ditch to keep dismounted troops from working in the ditch and creating gaps by hand. The wire and water also improve the ditch's effectiveness against attacking tanks. • Tie ends of tank ditches into existing obstacles such as steep slopes, wooded areas, and man-made structures. Ramps used in entering the ditch should be cut off and denied enemy access after completion of the ditch. This can be done with additional "dressing-up," using equipment or mine and wire obstacles. Mines should be used at the ends of the ditch to preclude being easily bypassed.When planning emplacement of tank ditches, keep this in mind: Soviet commandersrely on carefully rehearsed tactical formations for control in the attack. You candisrupt the momentum of the attack and force directional changes in attacking vehicles,thus exposing their vulnerable flanks. This is done by imaginative placement of ditcheswith other obstacles. Tank ditches should be placed in a series or, if time is available, in arandom pattern. Placing the ditch or ditches at 90-degree angles to enemy's avenue ofapproach may not always be the best tactical use. Consider the terrain and assetsavailable, and construct ditches in a pattern that will confuse, present good targets, andforce the enemy to use resources to breach.

DESIGN

The configuration of the most effective tank ditch has been a subject of much discussionand field testing with such constraints as time and equipment available, and soilconditions. The most efficient ditch is either a rectangular or triangular ditch.Frequently, you can save time, materials, and manpower by improving existing gullies orditches rather than constructing entirely new ones. One method is to excavate alongnatural drainage or contour lines to create a sidehill cut ditch. It would be beneficial ifthe ditch can be made to retain water. Muddy soil further degrades mobility. Placeantitank mines in the soil and antipersonnel mines in the bottom of the ditch todiscourage infantry soldiers. Depending on soil type, sides of ditches may have to bereinforced to prevent crumbling, and also to make the ditch more difficult to cross.Continuous direct fire should cover the ditch and force the enemy to deploy beforereaching the ditch. Scatterable mines on probable approach routes can further slowvehicular movement.

Rectangular ditches

ConstructionA ditch 3.3 meters wide cannot be "bridged" by tanks alone.A ditch 1.5 meters deep in consolidated, firm soil cannot be crossed by tanks or othervehicles without the aid of bridging or earthmoving equipment.A ditch 1.2 meters deep in firm soil should be considered "expedient" and capable ofonly a few minutes delay on the attacker.Rectangular ditches in sand must be greater than 1.6 meters deep to be considered morethan just an expedient ditch.Rectangular ditches should have a 1- to 2-meter berm on their friendly side which servesto increase the obstacle height, decrease traction to crossing tanks, greatly impedebreaching with scissor-type bridges, and keep the enemy from pushing the soil back intothe ditch without exposing their dozers or tanks with plows.Effects and resultsThe effectiveness of tank ditches is measured by the delay time imposed and targetspresented. It is a function of soil type and condition, and ditch width and depth. Therectangular ditch has proven to be the most effective in imposing delays in bothdirections. Results of tests on crossing rectangular ditches in various soil types are shownbelow. The ditch must be wide enough to prevent the tank from simply running over it,and narrow enough to force the tank to expose itself to our defense firepower. A 3.3-meter width (equivalent to a D7 dozer's blade) satisfies this criteria.

Triangular ditches

ConstructionEntrance slope is not critical in determining the effectiveness of triangular ditches.Subjective estimates suggest "the steeper the wall the better."A ditch 1.5 meters deep in hard clayey soils cannot be breached by tanks alone exceptunder unusual conditions.A ditch 1.2 meters deep in hard soil should be considered "expedient" and capable ofimposing only a few minutes delay on the attacker.Triangular ditches in sand must be greater than 1.8 meters deep to be considered morethan just an expedient ditch.To deny the use of the triangular tank ditch as a fighting position for the attacking armor,the spoil should be spread loosely on the enemy side rather than used as a berm. This willalso reduce tank traction when approaching the ditch.Effects and resultsResults of tests on crossing triangular ditches in various soil types and resulting delaytimes are shown below. Triangular ditches are two to four times faster to cross thanrectangular ditches when counterattacking. All tanks can easily cross from the friendlyside, and most smaller combat vehicles can counterattack across if following in laneswhere tanks have crossed.

scrapers, Combat Engineer Vehicles (CEVs), and bucket loaders can all be used for tankditching. Generally, the equipment is much more effective if used in teams rather thanalone. The M9s, dozers, and scrapers are most effective, while bucket loaders and CEVsare used as a last resort. Various combinations can be used. Some typical teamconfigurations could be: • Two M9s or dozers. • One M9 and two scoop loaders. • Two or more tractor/scrapers used in tandem. • One M9, dozer, and tractor/scraper used in tandem. (Generally, one M9 or dozer for two scrapers works best.) • Scrapers only; some may have to be bobtailed to use as pushers.This list is not inclusive. Units should practice and experiment using various equipmentand operator combinations to determine what works best for their area and whatequipment is available. Frozen or extremely hard soil will most likely have to be rippedwith dozer mounted rippers prior to digging.

METHODS

Following are four proven methods for tank ditch construction using organic engineerequipment.Two dozers or two M9s (ACES) as a team. In step 1, vehicle #1 will start the ditch andpush a load up to 9 to 10 meters (29 to 33 feet) from the start point, and then back up tostart the cut again. In step 2, vehicle #2 will push the load away from the ditch to form aberm as vehicle #1 is backing up. The team continues performing in this manner toconstruct the ditch. This "T-push" method is suitable for construction of tank ditches inall soil types.

One dozer and one scoop loader, grader, or CEV as a team. This step is performedthe same as the previous method except that the loader or CEV is used in place of vehicle#2. The grader is available to keep the berm straight and built up. After the ditch isconstructed, and if time permits, the berm can then be further shaped. Normally, thismethod would be less productive than the first method. Again, more than one team maybe used to construct the ditch.Tractor/scrapers in tandem as a team. Using tractor/scraper in tandem as a team is anexcellent method of tank ditch construction. The scrapers can have the pan attached oruse the tractor in a bobtailed configuration as a pusher to assist in loading. Each loadedscraper travels the full length of the tank ditch and exits toward the friendly side of theditch to spread the load and form the berm. A grader can also be used to shape andsmooth the berm which will reduce scraper-operator fatigue. "Bean bag" lights can assistduring night operation to guide operators and particularly to mark the turn out point. Thismethod utilizes only horizontal construction assets, and may free other diggers such asM9s, dozers, and bucket loaders to perform other missions.Tractor/scraper and M9s or dozers in tandem as a team. This method uses scrapers asearthmovers and generally requires a pusher (such as an M9, dozer, or bobtailed scraper)to assist loading of the scrapers. As the pusher and scraper exit the ditch, the scraper willturn toward the friendly side to dump the load along the berm; the pusher will exit on theenemy side and proceed back to the beginning of the ditch to pick up another scraper.This method produces excellent results, but requires training to reduce idle equipmenttime spent waiting for a pusher or scraper.

Operator training is an absolute must to attain maximum production. Experimenting with

various equipment combinations and soil conditions is valuable to determine the bestproduction for a specific area of operations and given equipment availability.

Production time

Basic production data of estimated construction times is shown for a 1.5 meter by 3.3meter ditch using the teams indicated. These production rates are based upon field tests.No significant differences exist between construction of a triangular or a rectangularditch. Valid test data does not exist for equipment combinations other than those listed. Construction at night

Tank ditching can be accomplished under blackout conditions. However, production willnot be as great, and certain precautions need to be taken. Equipment operators need anobject such as a "bean bag" light or flashlight with red lens to focus upon to assist indigging a straight ditch. Also, night vision devices, if available, are excellent foroperators to use. Scraper operators particularly need to have a guide or light to lead themout of the ditch and prevent turning out early and overturning. Night operations will be amust in order to emplace the number of tank ditches that will probably be necessary.Commanders should recognize this fact and train under conditions of darkness.

Construction by demolition

The utilization and effectiveness of explosives for tank ditching are still being studied.Considerable effort has been devoted to the subject. The concept of using liquid bulkexplosive and buried pipes is currently being tested and evaluated. This concept hassignificant advantages; for example, the pipes are buried during peacetime and, when atank ditch is required, the pipes are filled with explosive and detonated.The cratering methods described earlier can also be used to explosively create tankditches. Some clearing and shaping of the ditch will normally be required to increase itseffectiveness.

Construction using equipment and explosives

When encountering hard soils or rocky ground to be excavated, rippers used to loosenand break the soil aid in excavation and are the most economical. Should the rippers beunable to loosen the material for excavation, "preblasting," or the use of demolitionscould be employed using shaped, cratering, line, or buried tamped explosive charges tobreakup the ground. This technique will shatter the material sufficiently to makeexcavation easier and thereby raising production rates. An advantage to be considered isthat preblasting allows less powerful pieces of equipment, like the tractor/scraper, to digditches out of previously hard material.Should the tactical situation dictate that dozers be used for other tasks, preblasting maymake it possible to excavate with scooploaders. With dozers, preblasting maysubstantially increase production rates and decrease "downtime." Preblasting will surelydecrease wear and tear on machines and operators.For the combat engineer who has limited types and numbers of equipment, limitedcapability, and large numbers of tasks, equipment utilization in conjunction withpreblasting may turn an impossible tank ditch mission into merely a difficult one.

EXPEDIENT OBSTACLES

Expedient obstacles are basically created by using what nature has placed in the area.Imagination and ingenuity are the key factors in successfully constructing and employingexpedient obstacles. The possibilities for expedient obstacle creation are almost endless.A few of the more obvious are: • Abatis. • Log obstacles (including hurdles, cribs, and posts). • Rubble. • Junked automobiles and battle-damaged equipment. • Flooding. • Fires.

ABATIS

An abatis is an effective obstacle against tanks and other vehicles in a heavily-wooded

area with few roads or trails. An abatis can be constructed rapidly using demolition to felltrees. The trees should be felled at a 45-degree angle to the road or trail. The tree shouldremain attached to the stump to make the obstacle more effective and difficult to clear.To calculate the amount of explosive necessary for tree cutting, use the formula: D(diameter of the tree trunk, in inches) squared divided by 50, for a test shot.This formula is used to compute the amount of TNT required. The results of the test shotwill determine if more or less explosive is necessary for subsequent shots.Place the charges at a height of 5 feet above the ground. The trees will fall toward theside where the explosive is placed. One side of the abatis should be blown, and the otherside delayed, until the first row has fallen.If time allows, mines, wire, and booby traps can be added to make clearing moredifficult. Modular Pack Mine System (MOPMS) exploded on the obstacle adds anexcellent tank "killer" capability.

LOG OBSTACLES

There are many different types of log obstacles that can be constructed using localmaterials. Log obstacles are most effective when the lack of a bypass forces the enemy tobreach them. Although they are time and labor intensive, and locations for theiremployment are limited, they do not require much logistic support. Log obstacles can beconstructed entirely by hand. The availability of chain saws and bucket loaders orbackhoes will significantly reduce construction time. Log obstacles can and should beused in conjunction with other obstacles to increase their stopping power.

Log hurdles

Log hurdles can be constructed using logs greater than 10 inches in diameter. The size ofthe logs will dictate if the hurdles should be constructed of single logs or multiple logstied together. On level ground, log hurdles will not stop tanks, but will cause them toslow down. Hurdles will improve the effectiveness of other obstacles by slowing enemyvehicles and making them more vulnerable to friendly weapon fire.Log hurdles can stop tanks on uphill grades. The significant factor is determining howhigh to construct the hurdle. A field expedient method to determine the height of thehurdle is to use a stick about 12 feet long, stick the uphill end in the ground, and depressthe stick until it is level. The distance between the downhill end of the stick and theground is how high to construct the hurdle. The hurdle should be sited on the steepestpart of the slope and as near the top as possible.

Log cribs

Rectangular or triangular log cribs are used effectively as roadblocks where standingtimber is available, and where such an obstacle cannot be readily bypassed. Unlesssubstantially built, obstacles of this type are not effective against heavy-tracked vehicles.Cribs are strengthened by filling them with earth. It is preferable to obtain the earth bydigging a shallow ditch in front of the obstacle. Log hurdles in front of a log crib willforce vehicles to reduce speed and add to the effectiveness of the roadblock. Log posts

Posts are among the best antivehicular obstacles because each post presents breachingproblems to the attacker. There are no fast methods of breaching a belt of posts.Normally, the attacker will try to bypass such an obstacle. Therefore, post obstaclesshould be placed where bypass requires much time and effort. Posts should be hardwoodwith a minimum diameter of 40 centimeters (15.8 inches).All posts are buried 1.5 meters (5 feet) in the ground, either vertically or at a slight angletoward the enemy, and project between 75 to 120 centimeters (30 to 48 inches) aboveground level. The height should vary from post to post. The minimum acceptable densityfor posts is 200 per 100 meters (328 feet) of front. The spacing should be irregular, withat least 1 meter (3.3 feet), and not more than 2 meters (6.6 feet), between posts.The effect of post type obstacles can be improved, and the obstacles made more difficultto breach, by weaving spirals of barbed wire among the posts. Exploding MOPMS intothe obstacle after completion greatly increases its effectiveness. Conventional mines canalso be used to make the obstacle more difficult to breach.

RUBBLE

Rubble created as a result of combat in towns and villages can be used as obstacles incertain situations. Buildings can be intentionally rubbled by the 165 millimeter (mm)demolition gun on the CEV or by use of explosives. Mines added to the rubble willgreatly prolong the clearing process.

JUNKED AUTOMOBILES AND BATTLE-DAMAGED EQUIPMENT

When used to create road blocks, these items should be securely anchored to the groundif material and time permit. Using mines with the obstacle increases its effectiveness. FLOODING

Controlled burning of wooded areas, wooden bridges, and other areas is anotherexpedient obstacle method to prevent enemy use. Both flooding and burning generallyfall into the area of denial operations and will be closely controlled.Expedient methods of obstacle creation are limited only by imagination and ingenuity.The ability to find something that works when there appears to be nothing available is along-standing trait of the American soldier.

PRECONSTRUCTED OBSTACLES

Preconstructed obstacles are obstacles that are prepared in peacetime for rapid executiononce hostilities begin. They are generally designed and constructed not to be obtrusive orinterfere with vehicular traffic until executed. Preconstructed obstacles are generally ofthe following types: • Shafts sunk into the roadway at critical areas such as cuts, fills, and defiles, which will later be loaded with demolition to create road craters. • Shafts that are constructed for installation of a steel beam instead of demolition. • Bridges constructed with hollow demolition chambers in the piers and abutments. • Tunnels with planned cavities for demolition placement. • Massive concrete blocks suspended above or beside the roadway at selected locations which can be dropped into the roadway when needed.Preconstructed obstacles reduce the military effort for obstacle emplacement. They alsogreatly expedite the emplacement process once the appropriate alert or readiness postureis given.

PRECONSTRUCTED OBSTACLES IN NORTH ATLANTIC TREATY ORGANIZATION (NATO)

Once a location for a preconstructed obstacle is selected, a request is forwarded through

military channels to the host nation defense ministry. The location is based upon goodmilitary obstacle location techniques. The host nation will then evaluate the request andbe responsible for the construction of the obstacle and the demolition storage site if one isrequired.A target folder with all pertinent information will be prepared by the military regioncommand in whose area the obstacle is located. A copy of the demolition target folderwill be provided to the engineer unit responsible for execution of the obstacle.Wallmeister teams, a unit of the host nation Territorial Army, assist and support theengineer commander in all aspects of engineer technical subjects in the assigned area.The Wallmeister will perform maintenance and security checks of the preconstructedobstacle fixtures at regular intervals.

PRECHAMBER SHAFT SYSTEM

The prechamber shaft system consists of an array of several individual demolition shaftsdesigned to permit rapid execution of crater obstacles. The demolition shafts areconstructed of concrete pipe and located on roads, railroads, and bridge abutments.The individual demolition shafts that comprise the system are 4 to 6 meters (13 to 20feet) deep and 60 centimeters (24 inches) in diameter. The shafts are installed eithervertically or at an angle, and each shaft is closed by a steel shaft cover which resembles asewer manhole cover. Two detonation cord conduits are installed in a straight line fromthe interior of the demolition shafts to a metal cover box installed in the embankment orcurbstones of the road. These conduits are provided to accommodate the main andreserve firings systems.

The demolition material required for a prechamber shaft system is stored in a nearby 5-ton bunker complex and is earmarked for the sole use at its designated obstacle site. Theprestocked demolition material consists of: • The required number of DM41s, a 25-kilogram demolition block, cylindrical in shape similar to a large block of cheese (four cheese charges per 1-meter (3.3- foot) depth). • The appropriate number of nonelectric blasting caps and capwell adapters. • Sufficient detonation cord for both the primary and reserve ring mains and branch lines.In addition to the demolition materials, several special tools are necessary to install thetarget. One T-handle wrench, two shaft cover lifting hooks, and two loading poles areusually organic to most European-based combat engineer squads. In some instances,these tools may be stored at the obstacle site. The T-handle wrench and shaft cover liftinghooks are stored in one cover box, whereas the loading poles are stored in one of thedemolition shafts.The opening and loading of prechambers should begin at the prechamber shaft locatednearest the enemy and progress towards the friendly side. This is also the order in whichdemolitions should be off-loaded at each shaft. To open the shaft, use the T-handlewrench to remove the safety cap and loosen and unscrew the hexagonal nut. Insert thecover lifting hooks in the shaft cover; lift the cover off the shaft and place it to the side ofthe prechamber. Lift the traverse (located beneath the cover) by rotating it in a circularmotion until it hits a stop which will allow one end to tilt toward the top of theprechamber and be removed.To load a prechamber shaft with 25-kilogram cheese charges, the loading pole sectionsare screwed together and hooked into the carrying handles of the demolition charge. Thecharges are lowered into the shaft and stacked on top of the others. The last charge ineach shaft is lowered only after it has been dual primed nonelectrically with branch lines.The firing systems are installed by pulling the branch lines through the conduits whichrun beneath the road surface from the shaft to the cover box. Once the end of the branchline has been pulled through the conduct using the plastic lines provided in the conduit,the crossbar is replaced, and the shaft cover secured in place. Both primary and reservering mains are laid to the side of the roadway for attachment of the branch lines.The standard planning factor for complete installation of a three-shaft system dictates thata nine-member squad requires 90 minutes to complete the task.

BEAM POST OBSTACLE

The beam post obstacle is designed for blocking roads at defiles without destroying thepavement. The obstacle consists of steel I-beam posts inserted into preconstructed shaftsin the road width which prevents movement of all vehicles, wheeled or armored. Aminimum of two double rows of shafts must be preconstructed into a concretefoundation. Within each double row, the individual shafts must also be staggered. Eachbeam post shaft is 80 centimeters (31 inches) deep and has a steel cover. The I-beam postis constructed of sectional steel, 2.2 meters (7.2 feet) long and weighing 216 kilograms.When inserted into the shaft it will extend 1.4 meters above the road surface. Each steel I-beam post is equipped with locking devices which prohibit the enemy from pulling themout of the shafts.The beam post obstacle is emplaced by removing the shaft covers after unscrewing thehexagonal nuts with T-handle wrenches. Lifting hooks, organic to an engineer squad, areused to place the shaft covers to the side. As with the prechamber shaft system, removalof the crossbar allows access to the shaft. Carrying bars are employed to bring the I-beamposts to each shaft. Each beam is a designated four-soldier carry for lowering the postsinto the shafts. Once emplaced, the enemy side double row may be improved through theaddition of concertina wire and camouflage netting.The standard planning factor for complete installation of a beam post obstacle 12 meters(39 feet) in width, three double rows deep (requiring a total of 54 I-beam posts), dictatesthat two squads, each with nine members, require 2 hours to complete the task.

DEMOLITION FIXTURES IN BRIDGES

Demolition fixtures in bridges permit the destruction of such targets by expediting theinstallation procedures and simultaneously allowing friendly use of the bridge. There is ademolition target folder prepared for each bridge equipped with a demolition fixture.Primarily, three types of bridge fixtures exist throughout the European Theater:1 Charge mounting brackets.2 Demolition chambers.3 Demolition galleries.

1 Charge mounting brackets are sheet metal rails permanently mounted to the base ofthe supporting columns of a bridge. They are used to facilitate the placement of cuttingcharges and to insure their secure attachment. The 9-kilogram, DM19 cutting charge isequipped with lockable standoff sliding slats which are "L" shaped at the bottom forinstallation into the charge mounting brackets.

2 Demolition chambers are cavities built in the intermediate support columns andabutments of bridges. These types of fixtures are secured by means of a locked metalaccess panel. Demolition chambers are designed to accommodate large quantities ofconventional munitions, cratering charges, and satchel charges.

3 Demolition galleries are constructed in very large bridges. The galleries lead under theabutments of bridges or under the roadway and terminate in a demolition chamber orcavity. Because of the large quantities of explosives necessary to destroy such largetargets, the galleries are constructed to allow the uninhibited movement of personnelcarrying munitions to the chambers. The primary demolition material used to execute thistype of target is the 25-kilogram, DM41, cheese charge. Bridge fixtures of this naturehave permanently installed electric firing circuits through a series of conduits usuallyfrom one chamber to the next. Both the main and reserve firing systems end in adistribution box located at the abutments.Before preparing abridge for deliberate demolitions in accordance with the demolitiontarget folder, prepare the target for hasty demolition, if feasible. Because no demolitionmaterial is earmarked for hasty demolition, it must be taken from the combat load of thepertinent unit. As the demolition target is being prepared for deliberate firing, the chargesfor hasty demolitions will be removed.Planning data on required labor, material, and time for loading and preparing the targetfor firing can be found in the respective demolition target folder.

PRECONSTRUCTED OBSTACLES IN KOREA

The terrain in Korea is rugged with narrow armor approaches between mountains. Theneed for rapidly emplaced antiarmor obstacles, coupled with restricted terrain, makespreconstructed obstacles an excellent choice.Varying types of preconstructed, obstacles are found in Korea, the majority being thefalling block type. These are large concrete blocks suspended above or beside theroadway. Demolitions are stored nearby to blow the concrete block supports when theappropriate alert measure has been received and the tactical situation permits.Preconstructed obstacles are the responsibility of the Korean Government to construct,and the Republic of Korea (ROK) Army to maintain and execute.

ADDITIONAL OBSTACLES

Other types of in-place obstacles are tank walls, mined areas, and obstacles at selectedriver crossing sites. Preconstructed obstacles are key to the defense in that they areproperly located and can be executed quickly with minimal manpower. Tacticalconsiderations and advantages of preconstructed obstacles are numerous. For example,they-- • Are quickly executed. • Allow the use of the area prior to hostilities. • Reduce the logistic burden. • Reduce obstacle manpower requirements. • Enable maneuver plans to be prepared for in advance. • Assist in battle position location.Once installation of the demolition is complete, the obstacle can be immediately executedor delayed to fit the tactical situation. Preconstructed obstacles are complementary toother types of reinforcing obstacles and greatly assist commanders in fighting theAirLand Battle. ATOMIC DEMOLITION MUNITIONS

Atomic Demolition Munitions (ADM) are nuclear demolition devices used primarily forobstacle creation or denial operations. ADM can only be used when the authority toemploy nuclear weapons has been granted. In the AirLand Battle, commanders shouldplan for, request release of, and use nuclear weapons at the time when they will have thegreatest effect on the enemy. Special characteristics make ADM most desirable on thebattlefield. These characteristics are discussed in the following paragraphs. The SpecialAtomic Demolition Munition (SADM) is the ADM system currently in use. The SADMcan be carried by personnel, and is a low yield weapon fired by a timer mechanism.

CAPABILITIES OF ADM

Atomic Demolition Munitions have a much higher destructive power than conventionalexplosives. In order to achieve similar effects, a massive amount of conventionalexplosive would have to be used. The logistic and manpower requirements are greatlyreduced when ADM are used rather than conventional explosive. There is no deliveryerror with ADM. This is a significant advantage over any other type delivery systemwhen absolute accuracy is required such as a bridge or tunnel. Fallout, induced radiation,and collateral damage can be controlled or minimized by using ADM. A much largeryield weapon would have to be used to compensate for delivery error.For example, consider the destruction of major highway bridges. A subkiloton SADMdetonated subsurface in the center of the highway would create the desired obstacle.Considering delivery error associated with artillery-, aircraft-, and missile-deliveredsystems, and the inability to detonate these delivered systems at the surface or subsurface,yields in the 50-kiloton range would be required to assure creation of the desired obstaclewith any other nuclear system. The advantages resulting from using the lower yield ADMin tactical operations are significant.

ADM TARGETS Tunnels

Most tunnels cannot be severely damaged or destroyed with conventional explosives

because of the vast quantity required and the difficulty to concentrate the explosivepower of such a large volume at a single point. An ADM placed inside most tunnels willseverely damage them and create an obstacle that could take several weeks to breach.

Major highways

In order to effectively crater a major highway with conventional explosives, a large

amount of haul capacity, personnel, demolitions, and--most important--time would berequired.A low yield SADM detonated subsurface or on the surface would produce an obstaclethat the enemy could not breach with assault bridging. Breaching would require extensivefoundation preparation and installation of a fixed bridge. Even when not under fire, suchconstruction could require days to complete.

Bridges

Preparing a major highway bridge could require an engineer battalion's entire haulcapability and several company hours when using conventional explosive demolitions.The same bridge could be destroyed in a few minutes by an ADM firing team with a lowyield SADM.Other potential ADM targets include massive dams, canals, airfields, railroad switchyards, ports, industrial plants, power facilities, supply depots, and narrow valley defiles.

ADM EMPLOYMENT

The primary purpose of ADM is to create obstacles. The purpose of any obstacle orsystem of obstacles is to control enemy movement. This control means to stop hismovement, slow his rate of advance, or change the direction of his movement. Once theenemy has been stopped, he must decide whether to breach or bypass the obstacle. Heloses time during this decision process and presents a good target to friendly weapons. Ifhe decides to breach the obstacle, he loses more time because his rate of advance will beslowed. Forces awaiting the completion of the breaching operation will presentvulnerable targets. If he decides to bypass the obstacle, he loses time because of the lessdirect route to his objective. When ADM or any other obstacles are emplaced, friendlyforces should consider the bypass routes available and also create obstacles there or plandirect or indirect fire.In both offensive and defensive roles, the ADM acts as a combat multiplier. ADM usedto reinforce terrain will create very significant obstacles in terms of cratering and treeblowdown. When covered by direct or indirect fire and reinforced with scatterable mines,the enemy must expend considerable resources to overcome the obstacle and will mostlikely choose to bypass it. The residual radioactive contamination adds to the obstacle'seffectiveness. The overall effect is to cause local concentration of enemy forces, thuscreating better targets for conventional and nuclear weapon systems.

ADM in the offense

One of the roles that ADM can play in the attack is to provide protection to the flanks ofthe attacking formation, particularly in cross compartmented terrain. The ADM can beused to seal likely enemy counterattack avenues of approach. Another role for ADM inthe offense is to create obstacles behind the enemy to prevent escape from the attackingforces. Yet another is a close interdiction role to separate enemy first and second echelonforces by destruction of key highway and rail bridges in enemy territory. The ADM canalso be used in rear areas to disrupt main supply routes. Special Operations Forces (SOF)augmentation will most likely be required for ADM placed behind enemy lines. ADM in the defense

The greatest utility of ADM is in defensive operations. The effective creation of criticalobstacles can enable a relatively small force to hold off a large attacking force untilreinforcements arrive. In the defense, ADM is used to create key obstacles, blockdangerous avenues of approach, and deny the enemy use of important installations andfacilities. SUMMARY

Obstacles other than minefields span the spectrum from a simple log hurdle to a verycomplicated and precise bridge demolition. Methods, materials, and equipment span thesame spectrum. Several simple rules should be followed when selecting and emplacingobstacles other than minefields:Know threat capabilities and make sure that the obstacle or obstacles selected willaccomplish the mission.Know the capabilities of your soldiers and their equipment.Plan early; time is generally the most critical resource in obstacle construction.Tie the obstacle in with existing or other reinforcing obstacles.Cover the obstacle by fire if at all possible.Know the future mobility plan of friendly forces.Forecast logistic and haul requirements early.Train with combined arms team at every opportunity.Chapter 7

DENIAL OPERATIONS

Throughout history, denial operations have been an integral part of military operations.This chapter describes the authority and responsibilities for denial operations, andidentifies denial targets and methods in the overall planning process. AUTHORITY AND RESPONSIBILITY DENIAL TARGETS DENIAL METHODS DENIAL PLANNING SUMMARY

AUTHORITY AND RESPONSIBILITY

A denial measure is an action to deny the enemy the use of space, personnel, or facilities.It may include destruction, removal, contamination, or obstacle construction. Denialoperations have always been an important facet that, in many cases, determined theoutcome of wars. Denial operations over the years have ranged from the siege of forts orcastles to the destruction of ball bearing plants.There is a reasonably fine line that distinguishes denial operations from obstacleemplacement. Obstacles are normally emplaced to assist in destroying the enemy in theimmediate vicinity of the obstacle. Denial operations normally are not focused uponimmediate enemy destruction, but are designed to accomplish a more strategic purpose. Ifplanned and conducted properly, denial operations contribute to future operations andhave a far reaching impact on the battlefield. By their strategic nature, they also may havea much greater impact upon the civilian population. Flooding a valley or strategicallybombing an industrial complex are examples of denial operations that impactimmediately upon civilian population with a delayed effect upon military operations.

AUTHORITY

Denial targets have as their object the prevention of the enemy's beneficial use of somearea, facility, or resource. The targets frequently involve civil objects, and a judgmentmust be carefully made regarding the balance of military importance and the civil impactof destruction or evacuation. Evacuation or destruction must be made in full accord withthe Law of War. Accordingly, execution authority for denial targets must be centralized.The theater commander, subject to national policies and limitations, is authorized toconduct denial operations as a part of the overall campaign. The theater commanderestablishes the policies governing denial operations in the theater, and delegates planningand execution to service component commanders and subordinate joint forcecommanders. In developing denial policies, the theater commander will consider nationaland multinational policies and limitations, and possible reciprocal action by the enemy.Extensive consideration must be given to those facilities and areas required to supportcivilization in the post-hostility period regardless of the outcome of the conflict. Thelong-range social, economic, political, and psychological effects of excessive destructionof civil properties and material must be weighed against the military advantages gained.

RESPONSIBILITY

Corps commanders are responsible for translating the theater commander's policy intooperational plans and missions. Corps planners must perform a detailed analysis of theareas of operation. Specific targets are selected and assigned to subordinates forexecution. Prohibited targets must also be identified. Corps commanders will specifyconditions for execution. Any discretionary areas for subordinate commanders must alsobe specified, as well as any conditions or planning guidance.Division commanders are responsible for executing denial operations within their area. Inaccordance with the denial policy of the theater and mission assignments of the corps, thedivision plan provides for the denial of both military and civilian supplies, equipment,and installations with clearly identified military value. Division denial operations aregenerally a major task, requiring a high degree of technical skill and considerable timefor detailed planning, careful preparation, and execution.Brigade, battalion, and other commanders plan and execute denial targets as they areassigned missions in combat plans and orders. Denial operations are the responsibility ofall elements of the combined arms team. Although combat engineers are particularlysuited for executing denial operations with heavy equipment and demolitions, troops ofother arms and services can also help extensively. Transportation and other logistic unitscan conduct denial by evacuation of strategic equipment and materials. Air Force aircraftcan also contribute.To be successful, denial operations must be comprehensive. Thus, in warfare conductedin a modern state, denial operations will probably exceed the capability for engineerexecution alone. All available effort should be used.

DENIAL TARGETS

The most frequently selected denial targets and methods of destruction are discussed inthis section. Some of the reinforcing obstacles that have been discussed in previouschapters may also be used in denial operations.

DENIAL OF AREAS

Areas can be denied to the enemy; however, the length of the denial period may varywidely depending upon the type of denial method used and enemy capability and desire.Areas can be denied by: • Demolitions that deny access to the area. • Chemical or radiological contamination. • Floods. • Delayed-action explosives. • Construction of obstacles. • Isolation through interdiction or destruction. • Weapons fire. • Maneuver.

DENIAL OF INSTALLATIONS OR FACILITIES

For both strategic and tactical reasons, denial of key installations and facilities isdesirable inmost situations. Selected denial targets are integrated into the overall strategicand tactical concepts of the theater.

Railways

Effective denial of the railway system disrupts one of the enemy's principal transportationmeans. It necessitates a systematic denial of major structures, facilities, locomotives, androlling stock essential to the system's operation. To deny a rail net, it is necessary to cutall rail lines running generally parallel to the axis of enemy advance. The number ofcomplete cuts required depends on the length of delay desired. The best specific targetsare major bridges, tunnels, and defiles. The most important supporting targets are railwayterminal facilities such as roundhouses, shops, and marshaling yards, locomotives, androlling stock. When friendly forces desire to reuse facilities with a limited rebuildingeffort, the railway system may be effectively denied to the enemy by removing ordestroying special-type rail sections such as frogs, switches, or guardrails.

Highways

If the railway system is successfully denied, the enemy must depend on othertransportation. Highway system denial complements railway system denial and is ofconsiderable significance. It should be noted, however, that restoration of the highwaysystem by replacement or repair of bridges and other structures is generally easier andfaster than restoration of the railway system. Denial of the highway system, therefore, isnot effective for as long a time as denial of the railway system. Specific targets bestsuited for denial of a highway system are major bridges, tunnels, and defiles.

Airways

The airway system is highly important to the enemy for tactical and strategic operations,as well as for limited combat service support. Other than aircraft (which are evacuated ordestroyed), the specific targets are the airfields. Airfields can be denied by cratering therunways and destroying key supporting facilities. Atomic Demolition Munitions (ADM)are particularly suitable for this mission.

Petroleum, oils, and lubricants

Petroleum, oils, and lubricants (POL) system denial includes, in addition to thedestruction of bulk POL, the destruction of terminal storage, producing, refining, anddispensing facilities, as well as facilities for transporting bulk POL. The amount ofdestruction required varies, depending on the particular area under consideration, sincedestruction of a single key facility may eliminate the need for other destruction. Forexample, in an area lacking in oil production but having refineries, the enemy would beunable to use the refineries if all bulk POL handling and storage facilities were destroyed.

Electric power

Denial of major electric power systems impairs the operation of heavy industries. Denialshould provide for the systematic destruction of key generating plants. Since transformerstations form the heart of transmission systems, they are usually the most suitable denialtargets for disrupting power service with the least effort. The destruction of electricpower systems has a considerable impact on the local civilian population, and this factormust also be considered.

Communications

Disruption of major communications systems should provide for the destruction of

telephone and telegraph exchanges, repeater stations, and radio stations only. Morecomplete denial has a greater effect on the civilian population than on the enemy militaryeffort.

Inland waterways

In well-developed areas, particularly in Western Europe, inland waterways are highly

developed and carry a large part of total freight traffic. The waterways system can bedenied by destroying the dams, siphons, aqueducts, embankment or levee walls, locksand gates, barges, and other floating craft, as well as by obstructing the waterways.Drawdown of reservoirs can deny the enemy waterway use, and it can also be a means offlooding.

Utilities

The destruction of water, gas, and sewage systems ordinarily has little or no militaryeffect on the enemy, but has a most harmful effect on the local population. Unless amarked military advantage accrues, such as in the denial of water to the enemy in a desertor riverine area, utility systems should not be impaired.

Ports

Ports can be destroyed by nuclear or conventional demolitions; scuttling ships in harbors,

The denial of potable water is feasible in areas of the world where water is scarce.Storage containers and water sources such as wells or pipelines can be destroyed or thewater made unfit to drink. The possible adverse effect on the command and the localpopulation, however, must also be taken into account. Consideration should also be givento patrolling lines of communication to prevent water resupply from sources outside theimmediate area.

DENIAL OF MATERIAL

The destruction of material is a command decision and, except in extreme cases, is doneonly on authority of a division or higher unit commander. The general policy ismaximum evacuation and minimum destruction. Local civilian material of strategic ortactical value should be denied the enemy, particularly if he is critically short of someitems and requires the local items for further operations. The following items are amongthose which normally are denied to the enemy: • Nuclear energy facilities and related equipment. • Bulk POL stocks. • Locomotives and rolling stock. • Critical industrial components such as industrial diamonds, electronic equipment, ball and roller bearings, and aircraft engines. • Highway transport equipment. • Floating equipment and all harbor facilities such as hoists, cranes, locks, and ship repair facilities.

SELECTION OF DENIAL TARGETS

A denial operation carried to an extreme would remove or destroy everything that couldaid the enemy in any way. Because military assets are always limited, however, denialoperations must be planned and coordinated carefully to insure the military value of thetarget, and to determine the priority of destruction. Coordination with civil affairspersonnel is particular important. Effective denial operations will be targeted againstobjectives with high military value and full consideration will be given to the needs forparticular facilities in the post hostility period. Whenever possible, denial targets shouldbe selected to aggravate enemy strategic weaknesses and limitations. In selecting denialtargets, commanders should insure that they meet one of the following criteria. If thisdenial target is executed, loss of this capability to the enemy should: • Disrupt logistical support capabilities. • Prevent the use of local materials, supplies, and equipment to reinforce or augment offensive capabilities. • Require the diversion of significant engineer and operational efforts for repair, reconstruction, or rehabilitation to support military operations. • Delay the movement and distribution of replacements, supplies, equipment, and reserve units by forcing them to use secondary and low speed routes of advance and movement. • Restrict tactical or strategic mobility.Denial targets must meet the test of one of the above criteria. They must meet thosecriteria in a substantial--not incidental--manner.Furthermore, the means selected to deny the intended object should be one reasonablyavailable and capable of producing the least damage to civil property.For example, while it may not be appropriate to rubble a large portion of a town totemporarily close a major route, it could be justified to destroy a major bridge to closethat same roadway. However, such determinations must be made at appropriate levels ofcommand based on the circumstances at the time. Using the same example, if a rapidlyadvancing enemy force can be stopped most effectively by blocking a major route withrubble from destroyed buildings, such action would not be prohibited by the Law of War. DENIAL METHODS

REMOVAL

Evacuation of material is as much a part of denial operations as destruction and should

always be considered first. Evacuation must be started early and conducted in accordancewith prepared priority lists. Selective removal can be quite useful; however, the capabilityof the enemy to replace missing components or complete items must be accuratelyassessed. Selective removal is most profitable when the item removed is already criticalto the enemy. All like items (or selected components), including spares, must beremoved. Technicians may be required for meticulous selective removal.

DESTRUCTION

Explosives are generally used for destruction; however, other means can also be used.

Fire

Destruction by burning is a valuable technique; however, some materials that are

considered to be capable of burning will not burn. The advice of engineers should besecured before planning destruction by burning. The security of the tactical operationmust also be considered; intentions to withdraw may be given away by the burning.

Machinery

Rotating or reciprocating machinery usually requires lubrication to prevent damage from

friction. Such machinery can be damaged or destroyed by removing or contaminating thelubricants. The operator of the machinery or a technician is the best source of advice onrapid destruction methods of machinery items.

Water

Water can damage many items beyond repair. The effectiveness of water as a destructivemeans should be checked with a specialist on the item or material. Destruction by watercan usually be done quietly and without disclosing future plans or intentions.

Mechanical

Mechanical methods (such as breaking with a sledgehammer) can also cause destruction.An informed operator can achieve maximum damage with a minimum of effort. Cutting

Destruction by cutting vital metallic members of a structure with welding torches is

simple, easily learned, and a positive technique, but the equipment required is heavy.

Grenades

Thermate grenades are useful in denying certain targets; the intense heat produced fusesthe metallic portions of the target or distorts them beyond usefulness. The use of thermategrenades must be planned in advance so that they, and the experts who use them, areavailable.

Acid

Strong acids (such as nitric and sulfuric) properly applied can destroy many mechanismsand materials beyond economical repair; however, they are of marginal utility and ofsuch special or limited application that their extensive use is not practical.

Industrial

Many industrial items can be made unusable with a small amount of a contaminating oradulterating substance. No one substance is universally applicable therefore, technicalfamiliarity with the target is required.

CONTAMINATION

Contamination by chemical or radiological agents increases the denial effect by forcing

the enemy to decontaminate or to wait until the contaminants have decayed to a safelevel. Contaminants also can render an item temporarily unusable; however, items can bedecontaminated. Further, the contaminating agents deteriorate and lose their effectivenessunless periodically refreshed. Contamination is most effective when used with otherdenial methods.

ADM

Atomic Demolition Munitions (ADM) can destroy targets considered difficult or

impossible to destroy by other means. Normally, the theater commander publishesseparate instructions governing the employment of ADM. Subordinate commands expandthese separate instructions to fit their area of operations. Atomic Demolition Munitionscan destroy targets and accomplish missions that might normally be prohibitive forconventional explosives because of the logistic effort involved.Selection of an ADM target involves the consideration of several factors. Some targets,such as bridges and locks, usually can be quickly and adequately destroyed byconventional explosives; some, such as dams, may be suitable for demolition by eitherconventional explosives or nuclear weapons. Other targets may require excessiveamounts of conventional explosives and emplacement time, such as tunnels andunderground installations, or they may require rapid and positive destruction, such asairfields. Targets that require an excessive amount of labor or time for emplacement ofconventional explosives, because of their size or type of construction, are considered tobe hard targets and are particularly well suited for the use of ADM. The militarysignificance of a target is evaluated based on the effect that denial of the target will haveon the enemy's combat effectiveness. If the reduction in the enemy's combat effectivenessis such that a major advantage is gained, the target has high military significance. Targetslocated in or near large urban areas in friendly territory normally should not be attackedwith nuclear weapons; however, the advantages of destroying the target, particularly ahard target, must be weighed against the possible effects on the local population. Typesof ADM targets are listed below.

Defiles and tunnels

Defiles and tunnels are frequent ADM targets because they have high militarysignificance, are hard targets, lend themselves to effective blocking, and are seldomlocated near areas of dense population.

Bridges

Bridges are infrequent ADM targets since, with the possible exception of some heavymasonry and concrete structures, they can be sufficiently destroyed by conventionalexplosives. Complete destruction is seldom required.

Stream cratering

The use of ADM for stream cratering is infrequent; however, the great crateringcapability of ADM makes stream diversion possible to create obstacles where the enemyleast expects them. The crater lip can form a temporary dam, create a lake, causeoverbank flooding, and produce an effective water obstacle.

Dams and dikes

Dams and dikes are infrequent ADM targets since a reasonable amount of conventionalexplosives can normally accomplish the desired destruction.

Area contamination

It is possible to employ ADM in surface or shallow subsurface to create radiologically

contaminated areas as a part of an obstacle system; however, the requirement foroptimum meteorological conditions and the temporary nature of the contamination makethe use of ADM for this purpose infrequent. Unless contamination is renewed, theobstacle created is effective for only a few days. Airfields

Airfields are frequent ADM targets since the demolition of an airfield's runway complexis the most effective way to destroy the operational capability of an airfield.

DENIAL PLANNING

When denial policies are established, detailed planning must be accomplished at alllevels. Initial planning and policy guidance will be published, at theater level. Operationsplans and orders based on this guidance will assign denial targets and missionresponsibilities at corps and subordinate levels. A formal denial plan will be prepared byeach corps and division. Engineer terrain analysis teams will provide information on theuse of terrain in denial operations such as defining flood boundaries. Combat engineerswill be assigned a major role as they have the equipment, special knowledge, and skills toperform such work.

CONSIDERATIONS

The following items should be considered when establishing policy, formulating plans, orselecting targets: • Specific target areas (facilities) and items to be denied. • Degree of denial (denial or evacuation). • Priority for preparation and execution. • Command channels that will apply for the specific target. • Assignment of planning and execution responsibility. • Assistance to be provided or desired for protecting the targets from enemy interference. • Availability of special denial teams. • Limitations on the means of destructive denial. • Use of contaminants and/or nuclear devices. • Safety and security measures to be followed. • National policy restrictions (if any) of US or host nations. • Coordination required between US elements, joint commands, and allied forces. • Timing of planning and execution of the denial mission(s). • Allocations of available and local resources.

REQUIREMENTS

The initial requirement in the formulation of plans for denial operations is a detailedassimilation of all available maps and intelligence pertaining to the area of operations.Pertinent intelligence is studied to determine the enemy's vulnerability to denialoperations. The planner must analyze the area of operations, the military objectives, andthe location, characteristics, and optimum denial period of specific denial targets. Targetsmust be selected with care to insure that the enemy cannot readily compensate for theirdenial. The planner then selects those key elements of each target that should be attackedto make it inoperative for the predetermined optimum denial period. The planner's goal isto select those industrial, logistic, and communications systems that are most vital to theenemy's long-term operations. In addition, the systems selected should-- • Disrupt enemy logistic support. • Require the diversion of major effort to reconstruction and rehabilitation. • Prevent the use of local materials, supplies, or facilities necessary for continued operations. • Force all necessary supplies, especially heavy or bulky items such as POL and ammunition, to be transported over long and frequently disrupted lines of communications.

OBJECTIVES

The destructive work required for denial operations must not be confused with thatrequired for an obstacle system. Both involve extensive destruction and both may requiredestruction of the same facility.Consequently, there is an overlapping of objectives in the two plans. Normally, tacticaltargets of interest to a tactical commander in mission accomplishment are included in theobstacle plans of division, corps, and field army, unless restricted by specific orders orpolicies of higher commanders. Responsibility for destruction of these obstacle targetsflows through command channels.

COORDINATION

Responsibility for some significant tactical and strategic denial targets requirescoordination at all levels of command, since specific targets may be of suchoverwhelming importance to the theater and the theater commander's mission that thecommander is unwilling to delegate authority for destruction. For example, highway andrailway bridges crossing a major unfordable river may be of such strategic importancethat a high commander is willing to isolate some troops, perhaps a brigade, on the enemyside of the river rather than to risk capture of the bridge intact. On the other hand, adivision commander probably would consider blowing the same bridges only after thebulk of the division was safely across.

EXECUTION

In the denial plan, the theater commander includes instructions for the execution ofspecific denial missions. The commander may employ and control specially trained teamsor task forces to destroy all significant strategic targets, and make corps and theirsubordinate commands responsible for destruction of significant tactical targets. Thus,with primary interest in each type of target, the commander directs the preparation anddestruction of the target and overlapping of responsibility does not occur. On the otherhand, the commander may assign responsibility for executing all denial target missions tothe subordinate commanders in whose areas the targets are located. When theresponsibility is assigned to subordinate commands, the commander may also providespecially-trained denial teams to each echelon of command concerned to execute, advise,or assist in the destruction of technical targets.The actual organization and method for conducting denial operations are governed by thetechnology of the targets. Some denial targets are so highly technical that special unitsmust be organized and trained for the task. Other targets are so simple that any militaryunit can accomplish the required task with no more preparation than receipt of an order.In general, however, execution of denial target missions requires some technical orspecial training. The decision on the organization and method adopted is made only aftera careful analysis of the factors involved, including the adequacy of communications.When adequate communications are not available, authority for execution of all denialtarget missions must be delegated either to the tactical commanders in the areaconcerned, or to liaison personnel stationed at the target site.

OVERALL PRIORITIES

Because of the magnitude of denial operations and the limited time and means normallyavailable, missions are given priority in the order in which they contribute to the overalloperation. Those with the greatest immediate effect in reducing the enemy's combateffectiveness in the battle area generally have priority over those that have delayed orlong-range effects. For example, the denial of major airfields, bridges, or bulk POL, whentactically essential to the enemy, takes priority over the denial of major industrialfacilities.

SUMMARY

Denial operations are an important facet of modern warfare. The following guidelinesapply with regard to denial authority, methods, and planning.The theater commander establishes denial policy.Corps and division commanders plan and execute denial operations.Denial targets can be varied based upon METT-T.Denial methods range the spectrum.Denial targets must deny the most vital system to the enemy and should accomplish oneor all of the following: • Disrupt enemy logistic support. • Require the diversion of major effort to reconstruction and rehabilitation. • Prevent the use of local materials, supplies, or facilities necessary for continued operations. • Force all necessary supplies, especially heavy or bulky items such as POL ammunition, to be transported over long and frequently disrupted lines of communication.Priority of denial missions is based upon overall contribution.

Chapter 8

CONSIDERATIONS FOR SPECIAL OPERATIONS

United States forces prepare to operate in any part of the world as directed by the nationalcommand authority (NCA). The area of operation may contain terrain or climateextremes. Engineers must be prepared to support forces tailored to accomplish specificmissions. Engineers bring to this arena capabilities that are essential to battlefieldsuccess. This chapter outlines four special operations and discusses the preparation andproblems of each one. SUPPORTING LIGHT FORCES SPECIAL TERRAIN ENVIRONMENTS COMBINED OPERATIONS CONTINGENCY OPERATIONS SUMMARY

SUPPORTING LIGHT FORCES

Light forces include infantry, airborne, air assault, ranger, and special forces units.Engineer support to these forces will be extremely important, particularly against anarmor heavy enemy having equal or superior mobility. Countermobility support willnormally have the highest priority among engineer tasks. Well-planned, coordinated, andrapidly-emplaced minefields and obstacles can offset enemy advantages.Light forces are designed, organized, and equipped for air deployment and therefore havegreat strategic mobility. Engineer units organic to light forces are similarly organized andequipped. Generally, engineer equipment in light forces is smaller, lighter, and designedto support the specific missions of light forces.

INFANTRY

The infantry, division is most effectively employed in urban areas, mountains, jungles,and other terrain favoring dismounted operations. The infantry division is organizedwithout heavy weapon systems and requires increased support when facing a force moreheavily equipped. Countermobility support can help to offset the advantage of anopposing mechanized force. Early identification of enemy avenues of approach andexisting obstacles is extremely important in infantry operations. The infantry division isnot highly mobile and depends upon a carefully prepared battle plan on terrain that hasbeen well analyzed and reinforced.Initially, a good defensive location must be selected and obstacles sited to close highspeed armor approaches and create killing zones. Obstacle locations must support battlepositions and be placed in range of direct fire antiarmor weapons. Depending upon theterrain, all types of reinforcing obstacles could be selected. Extensive use will be made ofconventional minefields. These obstacles should be emplaced as early as possible. It isnot necessary to have battle positions occupied prior to obstacle emplacement. During thebattle, scatterable mines should be used on targets of opportunity and also to enhance thestopping power of other obstacles such as tank ditches and road craters.

AIRBORNE

Airborne forces have the greatest strategic mobility of any US combat force. Oncedeployed, their tactical mobility is limited and they are vulnerable to ground attack bytank or motorized units. Engineer units supporting airborne forces are light and do nothave the digging and earthmoving capability of other engineer units.Upon landing, the first priority of airborne forces is to secure the airhead. Rapid obstacleconstruction is required. Demolition type obstacles and rapid mining using conventionalor scatterable mines will be the initial countermobility requirement. High speed armorapproaches are cut or mined and have the highest priority. Demolitions and mines will belimited and every effort must be made to insure that their expenditure will inflict damageto the enemy. Maximum use should be made of local equipment and materials. Obstaclesmust be covered by antitank fires and employed in depth. Survival of the initial force iscritical. Well-planned and rapid countermobility effort will be a significant factor.As the airhead is secured, more intensive obstacles can be planned and constructed.

AIR ASSAULT

Air assult operations play a major role in either offensive or defensive operations. Theability to quickly mass or disperse forces provides the commander with considerableflexibility. Air assault operations are characterized by careful planning and deliberate,bold, and violent execution.Like the airborne force, the air assault force is vulnerable to attack by enemy motorizedand tank forces. But the battle is very different. Air assault engineers emplace obstaclesto give maximum time for antitank weapons engagement. Often, engineer supplies arelimited and must be airlifted to the work site. Countermobility is normally the highestengineer priority. The distinction between offense and defense is never particularly clearin air assault operations. Ordinarily, the division is fighting in a large area and can chooseoptimum terrain for ground battles that focus on enemy units. Obstacles are used to createkilling areas. Usually, the ground units shoot from restrictive terrain into trafficablecorridors where the obstacles are specifically sited to enhance killing. Other obstacles aresited for close-in protection of ground units and to facilitate disengagement. Engineersaccompany raids to establish obstacles and battle positions that isolate the enemy unitbeing destoyed. Other pure engineer insertions install obstacles to support attackhelicopter and tactical air kill zones. As combat power is quickly concentrated on theenemy unit, engineer demolition teams are used to complete the annihilation of theenemy force. Air assault combat power in the area then evaporates to other places oflesser vulnerability while major obstacles (such as big bridges and tunnels) that wereclosed early prevent enemy pursuit. Because withdrawal is by air, the need for reservetargets is minimal.

SPECIAL TERRAIN ENVIRONMENTS

engineer units are equipped for employment within a wide range of conditions,environmental extremes usually require specialized techniques, procedures, andequipment. The engineer, as an integral part of the combined arms team, takes on addedsignificance in extreme environments. As the maneuver commander's terrain experts,engineers must fully understand and use the special advantages and disadvantages thatsuch environments provide for countermobility. There are five special terrainenvironments encountered in areas of US strategic concern today:1 Mountains.2 Jungles.3 Deserts.4 Cold climates.5 Urban terrain.

1 Mountains. Obstacles are particularly effective in mountainous terrain, since bypass is

very difficult. Properly placed and covered by fire, obstacles can serve as a decisive forcemultiplier by making approaches and key routes impassable. An ADM which isdetonated to destroy a mountain tunnel or close a high pass could close off an area tovehicular traffic for months.Both antitank and antipersonnel mines are best laid along the relatively narrowapproaches suited for vehicular movement. In mountainous terrain, scatterable mining isused more frequently than conventional mining. The use of scatterable mines should beconsidered as a means to conserve engineer resources and preserve the flexibility of themaneuver commander when short duration minefields are required. Artillery and airdelivered mines are especially useful in delaying second echelon forces moving throughmountains.Other types of obstacles can also be used such as road craters, log cribs, and abatis.Destruction of bridges and creation of landslides to block routes are other possibilities.Together with the natural ruggedness of mountains, obstacles can be effectivelyemployed to deny the enemy terrain, and delay and impede his movement. They are sitedby the maneuver forces commander in coordination with available weapon systems andrestrictive terrain.

2 Jungles. A jungle is that area within the humid tropics with a dense growth of treesand other vegetation. Vegetation in jungle areas includes lowland and highland tropicalrain forests, dry deciduous forests, secondary growth forests, swamp forests, and tropicalsavannas. The difficulty of movement through jungle growth impedes militaryoperations. Visibility is usually less than 30 meters. Good roads are rare and usually arenarrow, winding, and incapable of supporting sustained military traffic. As the jungleitself is an effective obstacle to vehicles, reinforcing obstacles are normally confined toroads, trails, and patches of cleared ground. Antipersonnel mines are effective in junglesbecause of the large amount of dismounted movement. Antipersonnel mines can beeffectively employed to delay, stop, and canalize the enemy, and to serve as warningdevices.The jungle lends itself to the use of mines and booby traps. The characteristics of thejungle cause emplacement to be comparatively easy and detection to be extremelydifficult. Because mines have a tendency to shift during heavy rains, they must besecurely implaced.

3 Deserts. The key to successful execution of the engineer countermobility role in desertoperations is mobility. Engineers must move about the battlefield responding to missionrequirements in a timely manner. Due to the mobility inherent in desert operations,obstacles must be extensive and used in conjunction with each other and any existingobstacles. Isolated obstacles are bypassed easily.The primary means of creating obstacles in the desert is through mine warfare. Mines,both conventional and scatterable, will be used to-- • Deny terrain. • Delay and disrupt enemy movements. • Interdict reinforcing echelons and reserves. • Protect flanks and rears. • Isolate an objective. • Disrupt threat retrograde.Mines are easily emplaced in a sand desert where blowing sand will effectively concealevidence of emplacement. However, the following potential problem areas must beconsidered: • Large quantities of mines are required for effectiveness. • Sand can cause malfunctioning. • Shifting sand can cause mine drift. • An excessive accumulation of sand over the mines can degrade performance. • Sand may be blown away, thus exposing the mines. • Minefield marking may be counterproductive.Scatterable systems will be heavily relied upon in deserts because of the manyadvantages they offer. Scatterable minefields-- • Can be rapidly and remotely emplaced. • Reduce engineer effort. • Preserve maneuver flexibility for friendly forces by self-destructing.Conventional mining will also be used to establish desert strongpoints and to mine roadsand trails.Many desert villages depend on irrigation canals. These canals, when tied in with otherobstacles, are effective in halting armor. In suitable terrain, antitank ditches that exceedthe vertical step of enemy main battle tanks may be used. Because antitank ditches cannotbe concealed, they must be dug so they do not outline a defensive front or flank. Theyhave the advantage of not requiring as much logistic support as minefields. They must becovered by fire and mined to prohibit their use by enemy infantry as ready-madetrenches.

4 Cold climates. In planning obstacles under cold climate conditions, several factorswhich complicate engineer tasks must be taken into consideration: • Extreme and rapid temperature changes. • Wind, snow, and ice storms. • Alternate thawing and freezing. • Terrain features such as mountains, tundra, and muskeg. • Flooding.More time must be allowed for preparation of obstacles systems in cold temperatures dueto decreased efficiency of personnel and equipment, and increased travel times.Both antitank and antipersonnel mines are adaptable to cold climate operations. Ifpressure type mines are used, solid support for the mines is necessary; otherwise, whenpressure is applied, they will sink in soft snow. If mines are buried too deeply in snow, itis possible that detonation will not occur because moisture may freeze and hinder theworking parts. In snow-covered terrain, mines can be painted white for camouflage.When using conventional antipersonnel mines, tripwire firing systems are most effective.Tripwires should be placed at various levels above the snow. Arming large quantities ofconventional mines can be a difficult task in cold weather. On scatterable antipersonnelmines, snow may cause tripwires to malfunction. All mines can be placed on ski orsnowshoe trails, but winter storms can cover or expose them.In summer, the thousands of lakes, rivers, and swamps of the cold climate regionsprovide formidable obstacles to armor and personnel. In winter, when these bodies ofwater are frozen to sufficient depth, they provide excellent avenues of approach. A frozenbody of water may become an effective obstacle by using explosives to break the ice. Inblasting, the explosive is placed under the ice to take advantage of the excellent tampingeffect of water. Holes are cut or blown in the ice by explosives, and the charges are heldin position under the ice by bridging the holes with poles.Existing obstacles in cold climates often need very little reinforcing. For example, snow-covered or icy slopes can seriously impede troops and vehicles; fallen trees covered withsnow can delay troops on skis or snowshoes; avalanches make excellent obstacles forblocking passes and roads. Avalanches hinder friendly forces as well as enemy forces,but in some cases likely locations for avalanches can be predicted. By artificiallyinducing the avalanche, it is possible to cause the slide at the desired time.There are many types of reinforcing obstacles which are appropriate for winter use.Barbed wire normally employed makes an effective obstacle in soft, shallow snow.Concertina wire is another quick way to improve snow-covered obstacles. Tripleconcertina is especially effective since it is easy to install. Along trails, roads, and slopes,abatis can cause much trouble for skiers and vehicles. Obstacles can be formed bypumping water on road grades; the ice that results will seriously hamper vehicular traffic.

5 Urban terrain. Unlike deserts, mountains, and jungles, which confront the engineerwith a limited variety of fairly uniform recurring terrain features, the urban battlefield isan ever-changing mix of natural and man-made features. Operations in urban areasrestrict maneuver and are time-consuming, but they will be difficult to avoid because ofthe expanding urban belts in many industrialized countries. Tactical doctrine stresses thaturban combat operations are conducted only when required, and that built-up areas areisolated or bypassed if possible.A built-up area compares closely with a fortified area because it provides an environmentwhich is easily converted to a fortified area. For these reasons, conditions favor thedefender. Ready-made strongpoints exist with good cover and concealment. The attackeris easily canalized and surprised. Fields of fire and observation are dramatically reduced.Units in urban areas are vulnerable to nuclear and chemical attack because of the relativelack of dispersion and mobility.Obstacles must be planned in depth, starting well forward of the urban area to delay andcanalize the threat force. Possibilities for obstacles are unlimited in urban terrain. Theobjective will be to deny the enemy freedom of rapid advance through the built-up area.Obstacles, covered by fire, will accomplish this. Mines, wire, craters, and rubble allcreate effective obstacles. Streets are barricaded to halt tanks at the optimum range ofantitank weapons. As enemy vehicles are disabled, they, too, will become obstacles asstreets are clogged. Antipersonnel mines with antihandling devices are employed withantitank mines around and within obstacles, and are covered by fires to make reductioncostly and time-consuming. Since the enemy will probably be forced to dismount in orderto continue the attack, antipersonnel type obstacles must be integrated throughout theobstacle plan.

COMBINED OPERATIONS

The US Army engineers must be prepared to support combined operations conducted by

forces of two or more allied nations acting together to accomplish a single mission. InEurope, under the North-Atlantic Treaty Organization (NATO), and in Korea, as part ofthe US-ROK Combined Forces Command (CFC), engineers will operate underprocedures and principles that have been planned, practiced, and standardized inpeacetime.

NATO OPERATIONS

Countermobility in Europe has some unique considerations due to the amount of timerequired to emplace obstacles. The potential speed and mobility of threat forces havemade detailed obstacle planning during peacetime an absolute necessity. The NATOforces in Europe have made extensive use of preconstructed obstacles, such as pre-chambered bridges and roads and steel girder obstacles, as well as the use of obstaclefolders. When preparing obstacle plans on the battlefield, the tactical commander musttake these preconstructed obstacles into consideration.

Obstacle folders

When time permits, as in planning during peacetime, obstacle folders are prepared. Fornon-nuclear demolitions, STANAG 2123 governs. The non-nuclear obstacle folder isprepared to provide all information required to destroy a target. It consists of thefollowing four parts:1 Detailed target location.2 Location of explosives and equipment.3 Orders for preparing and firing.4 Demolition report.Situations could occur where the unit responsible for emplacing and/or firing ademolition is of a different nationality than the unit preparing the folder. To allow for thispossibility, the obstacle folder is prepared in a multilingual form. The NATO obstaclefolders are prepared in-- • Language(s) of the units concerned. • Language of the host nation. • One of the two official NATO languages (English or French).Notes on maps, plans, sketches, and so forth are to be in one language only with atranslation of relevant items shown at the bottom of the page.

Mine warfare

When employing minefields in NATO countries, all provisions of STANAG 2036 mustbe followed.

National territorial forces

In the Central Region, forward of the corps rear boundary, responsibility for denialoperations is maintained by the German government through the "Wallmeister"organization. This organization of highly-qualified engineers performs the followingfunctions: • Control all preplanned obstacles such as prechambered bridges and roads. • Assist allied engineers in procuring local resources such as lumber and crushed rock. • Provide special and up-to-date maps of the areas. • Conduct extensive reconnaissance to locate and record power plants, dams, water points, bridges, and so on.German Territorial Forces provide coordination for host nation support to US Army andother allied forces. Their responsibility begins at the corps rear and extends west to thenational boundary. Their primary engineer missions include: • Insuring logistical and engineer support to NATO forces within the scope of national agreements. • Supporting NATO forces by providing local resources.United States Army engineers must make immediate contact with the Wallmeisterorganization or territorial force commander in the area of operations.Virtually every NATO nation has organizations similar to the German Territorial Forces.United States Army engineers must be familiar with local organizations and foster closeworking relationships prior to the outbreak of hostilities.

KOREAN OPERATIONS

The chief instrument for the defense of Korea is the Combined Forces Command (CFC).The CFC Commander-in-Chief exercises combined operational command/control over allforces defending Korea. As in NATO, important differences in capabilities, doctrine, andequipment exist. Unlike NATO, few STANAGs currently exist to alleviate thesedifferences.United States Army engineers in Korea are part of a command structure which hasdeveloped since the Korean War. As in NATO, US Army engineers stationed in Koreaconduct extensive interoperabililty training. The factors that affect engineer operationsand interoperability in Korea include: • North Korean Threat. • Terrain and climate. • Command relationships. • Coordination, liaison, and language.

North Korean Threat

United States and Republic of Korea (ROK) forces face the forces of North Korea alongthe 151-mile demilitarized zone (DMZ). North Korean forces are positioned well forwardin an attack posture and are in a high state of readiness. The highly-policed North Koreansociety makes intelligence collection difficult. Thus, North Korea has the capability tolaunch an attack with little warning.

Terrain and climate

While much of the mountainous Korean terrain favors light infantry operations, twomajor avenues of approach from the north are suitable for mechanized/armoredemployment. These two avenues of approach lead directly to Seoul, the capital of theROK, only 40 miles south of the DMZ. Thus, the defense of Seoul depends on containingan enemy attack as far north as possible. This is a key factor in the defense plans ofKorea. Heavy rains in summer often cause damaging floods which severely restrictmobility, while freezing rice paddies in winter increase mobility. Additionally, themountainous terrain tends to channel vehicular movement. The mobility-countermobilityroles of the engineers will be critical during any allied operation.

Command relationships

Most engineer units in Korea will remain in their national organization. If a cross-attachment of allied engineer units is effected, the command relationship should beoperational control (OPCON).

Coordination, liaison, and language

The CFC structure in Korea requires a high degree of coordination between US and ROKengineers at all levels. There are Combat Support Coordination Teams from HQCombined Field Army, First ROK Army (FROKA), and the Third ROK Army(TROKA). These teams facilitate day-to-day working relationships between US andROK units, and have elements familiar with engineer planning.The language barrier, coupled with cultural and doctrinal differences, poses potentialproblems for US and ROK engineers. Early combined planning for engineer operations,and the use of trained liaison teams and Korean Augmentation to the US Army(KATUSA) personnel, will help to alleviate some of the problems.

CONTINGENCY OPERATIONS

A requirement to deploy US Forces may develop in any part of the world, and in all typesof terrain or climate. There are two basic scenarios in which US armed forces might beinvolved. Combat might begin in an area where US armed forces are already stationed(combined operations), or in an area where there are a few or no existing US bases orunits (contingency operations). In the latter case, deployment will probably occur undercircumstances of great urgency. The lack of US military installations and supportfacilities generally means a requirement for extensive engineer support.The US contingency force must be capable of defeating a threat which varies fromguerrilla activity to well-organized regional forces armed with modern weapons.Contingency forces must be prepared for chemical and nuclear warfare, and also for airattack by modern, well-equipped air forces. Logistics and base support requirements willdictate operational capabilities to a much greater extent than in a mature theater.The engineer force structure of the contingency force must be carefully tailored. Generalcontingency plans must allow for rapid changes in the tasks, organization, and support toadapt to widely varied potential threats and environments. The composition of thecontingency force must be sufficiently light to allow rapid strategic deployment. At thesame time, it must possess sufficient combat power and earthmoving support to providenecessary engineer support. The lack of logistic support for the deployed task forcerequires a capability to fully exploit whatever host nation support is available.Deploying engineer forces are responsible for all engineer functions. Initially, there willbe little back-up support for engineers organic to combat forces. Engineer support in thecountermobility effort will be essential. Due to the light force structure and limitedlogistical support, priorities must be established to determine where the engineers canbest be utilized. The situation will determine whether shifts from those priorities arenecessary.

SUMMARY

Countermobility support to light forces

Countermobility is normally the highest priority engineer task.Countermobility is essential against mechanized enemy.Countermobility support must be rapid and well-coordinated.Special terrain environmentsCountermobility tasks must be designed to the terrain requirements.Terrain and climate restrictions require ingenuity to select and emplace the propercountermobility asset.Combined operationsPreconstructed obstacles are generally in place.National agreements may govern.Familiarity with allied methods and equipment is essential.Contingency operationsCountermobility efforts must be tailored to specific threat.Countermobility will aid sustainment of the force.Deployment restrictions may dictate that countermobility efforts are primarily mine anddemolition oriented.Appendix A

OPERATIONS ORDERS

The purpose of this appendix is to provide sample operations orders, plans, and annexesthat are commonly used by engineers and maneuver units in planning and executingcountermobility tasks. The sample orders and plans provided in this appendix wereextracted from FM 101-5, appendix G, and may be used as guides. Providing an accurateportrayal of the commander's concept and intent is critical in writing plans and orders. CORPS OPERATION PLAN CORPS TASK ORGANIZATION ANNEX ENGINEER ANNEX FORMAT CORPS ENGINEER ANNEX CORPS OBSTACLE APPENDIX TO ENGINEER ANNEX CORPS DENIAL APPENDIX TO ENGINEER ANNEXAppendix B

STRONGPOINTS

This appendix gives insight to develop a strongpoint into the mission. A strongpoint isthe cork in a bottleneck formed by terrain, obstacles, and units. This countermobilitytactic is essentially an antitank "nest" which physically cannot be overrun or bypassed bytanks, and which can be reduced by enemy infantry only with considerable expenditure oftime and forces. It is similar to a perimeter defense in that it is developed to defeat anattack from any direction. It is distinguished from other defensive positions by the keyuse of terrain and by the time, effort, and resources dedicated to its development. PLANNING CONSIDERATIONS ENGINEER EFFORTS SCENARIO

PLANNING CONSIDERATIONS

In some cases, the brigade or division commander may direct that a strongpoint beemplaced by a battalion or company-sized unit. There are several important aspects abouta strongpoint that need to be clearly understood. A strongpoint is not routinelyestablished. It is established only after the commander determines that a strongpoint isabsolutely necessary to prevent decisive penetration of the defensive system by enemyarmor. The decision must be carefully weighed against the following impacts: • If the strongpoint is bypassed, the defenders may become encircled. • The force establishing the strongpoint loses its freedom to maneuver outside the strongpoint.Assignment of this mission presupposes that-- • Terrain which lends itself to the mission exists. • Maneuver units and fire support assets required to defend the strongpoint are available. • Time, supplies, and equipment necessary for preparation are available.A strongpoint must be emplaced far enough from the line of contact to provide thenecessary development time. Terrain to the flanks must restrict the advance of themounted attacker. The maneuver commander, upon receiving the mission to establish astrongpoint, immediately conducts a joint reconnaissance with the leader of thesupporting engineer element to establish the optimum application of available assets. Thestrongpoint is prepared in accordance with the following broad priorities:  MAKE THE POSITION PHYSICALLY IMPASSABLE TO TANKS.  PLAN INDIRECT FIRES AND SCATTERABLE MINES TO SLOW, DISRUPT, AND CANALIZE THE ADVANCING ENEMY.  ENHANCE THE KILLING POWER OF ANTITANK WEAPONS WITH OBSTACLES.

ENGINEER EFFORTS

Building block concept

The building block approach permits engineer efforts to be planned in terms ofmanpower, equipment, time, and materials for typical emplacement tasks. This conceptprovides flexibility to the engineer in that estimates can readily be made for anystrongpoint size or design. The building blocks are as follows: • Recon the area with the maneuver commander. • Determine the required effort. • Determine critical tasks. • Allocate resources. • Generally, work from "inside" to "outside." • Use all available effort.Essential tasksThe following five essential engineer tasks must be performed for all strongpoints. • Prepare close-in obstacles to prevent being overrun by tanks. • Prepare hull down positions for fighting vehicles. • Emplace obstacles at maximum ranges of antitank weapons. • Construct protected connecting routes between positions. • Plan and coordinate for scatterable mines.

SCENARIO

A brigade consisting of four battalion task forces is defending along a corridor. Itsmission is to stop the enemy in sector, and prevent him from gaining access to the morefavorable terrain. The strongpoint must be completed within 10 hours.The highway in the valley is the only high-speed approach through the sector. This roadis vital to maintaining the momentum of the enemy's attack, and also vital to his ability tosustain ground operations. The alternative is to attempt the time-consuming maneuverover restrictive terrain.The brigade commander knows that the threat will move its motorized forces on the high-speed avenue of approach. If the commander fails to control the road, the brigade defensewill crumble throughout the sector. The brigade commander determines that a strongpointis absolutely necessary to prevent a decisive penetration of the defensive system byenemy armor.

The best way to block the enemy is to establish a strongpoint in the valley. The valley isopen, flat, and approximately 4 kilometers wide. The hilly terrain on both flanks providesexcellent sites for battle positions. The Blau River and the marshy areas all along itscourse further narrow the valley. A succession of small villages along the valley floorprovides excellent battle position locations, but fails to fully block the avenue. Near therear boundary of the sector, only the town of Lingen offers a position which blocks thevalley. In conjunction with the fish hatcheries, the Bazil Burg, and Schloss Wolf, thetown forms a chokepoint. It fulfills all the requirements of a strongpoint for the tacticalplan, and can readily be established within the time constraints. The brigade commanderassigns the mission to the mechanized infantry battalion. The commander of thenormally-associated engineer company and the battalion commander made a joint reconof the area and prepared resource and time estimates.TasksIn addition to the five essential engineer tasks, the following tasks are also performed forthis strongpoint. The tactical commander could vary these additional tasks as the situationchanges. • Analyze terrain. • Construct other positions that exceed maneuver unit capability. • Improve positions. • Improve obstacles.The maneuver units can handle the bulk of the preparation of the individual and lightcrew-served weapon positions, thus allowing the engineers to concentrate on keypositions, the obstacles, and interconnecting routes. The Combat Engineer Vehicle (CEV)is assigned to work in the town where its demolition gun and blade could both be used tocreate and use rubble for positions, obstacles, and protected routes between positions.Although maneuver units are trained in and have demolitions as part of their basic load,engineers assist with technical advice in their use. Most of the initial demolition workinside the town is done by the maneuver units. The engineer platoon effort, to includedemolitions, initially goes into building the obstacle system. When that is finished, theplatoon will join the maneuver units in improving positions by using sandbags, rubble,and locally available building materials to strengthen walls, beams, and overhead cover.Engineer equipment continues to haul and position earth for sandbags and other shoringmaterial.Sequence of effortThe maneuver units, assisted by engineers, prepare fighting positions, shelters, andprotective obstacles using materials from basic loads. An engineer squad uses explosivesand assists the maneuver units in employing demolitions and strengthening buildings.At the same time, the dump truck and loader stockpile earth in each maneuver platoonarea for filling sandbags, and the dozer and CEV create and handle rubble for obstaclesand covered routes. Outside the town, the ACE and backhoe/loader digs antiarmorpositions and the interconnecting trenches.Concurrently, the engineers begin work on the obstacle plan, which was worked out aftera joint reconnaissance by the infantry battalion commander and the supporting engineerplatoon leader. The plan ties in minefields, bridge demolitions, and road craters withthese obstacles already present: the town, the sunken road, and the Blau River with itsassociated ponds, marshes, and steep slopes.

The scenario is depicted below.

Appendix C

OBSTACLE NUMBERING SYSTEM

In developing an obstacle plan, a uniform numbering system is used to identify obstacles.

This numbering system is used with maps, lists, obstacle overlays, and annexes. Arecommended numbering system with an example follows: Unit Designation Unit Type Target Number

23XX A 0023

The unit designation identifies the division or corps (or other separate command) thatauthorized the target. Examples are:2XXX - II Corps23XX - 23d DivisionThe unit type is a letter that identifies the type or branch of the designated unit. A corpstarget has no letter designation. The following code is used for unit type:A - ArmorC - CalvaryH - AirmobileI - InfantryM - MechanizedP - AirborneExamples are:2XXX - II Corps23XXA - 23d Armored Division82XXP - 82d Airborne DivisionThe target number is a three-or four-digit number assigned by the unit to a particulartarget. Corps and division break down blocks of numbers to subordinate units. Corps usestarget numbers 001 through 999. The division number system is:Division uses target numbers 0001 to 09991st Brigade uses target numbers 1001 to 19992d Brigade uses target numbers 2001 to 29993d Brigade uses target numbers 3001 to 3999(NOTE: Further subdivision of brigade number blocks is not permitted.)Target numbers 4000 through 9999 may be assigned to divisional units as required, or toother units operating in the division's area of responsibility. Examples are:2XXX0157 - II Corps, target number 15723XXA1021 - 1st Brigade, 23d Armored Division, target number 1021It is not necessary to use the complete target number on a division or brigade obstacleoverlay. Within a particular unit, the unit designation and type are dropped. Instead of23XXA0784, the number 0784 is used. For obstacles authorized or ordered by other unitswithin the same overlay, the full target number must be used. The number 2XXX0023would be a II Corps target.If necessary to distinguish them, denial targets are given a suffix "D" such as2XXX0057-D.It is a serious mistake to add any of the following as part of the obstacle number. These"add-ons" rapidly reduce the system to unworkability. • Further symbols. • Subordinate number block assignments. • Additional information such as status, target-type location, preparing unit, and relation to a supply facility.Appendix D

STANDARD OBSTACLES

This appendix provides time, personnel equipment, and material estimating factors forobstacle planning. Reconnaissance or experience in a particular area may require that theplanning factors be modified. The estimates given in this appendix are generally basedupon "standard" sizes and types of obstacles. The basic purpose of the "standard"obstacle concept is to permit rapid estimating for resource requirements. Early estimationof resource requirements assists in personnel allocation and early requisition of materialto accomplish the mission. For instance, if 40 hasty road craters are required in aparticular obstacle plan, multiply the resources required for the hasty crater to get areasonable estimate of the resources required. The estimates will not always be asaccurate as an on-site reconnaissance; detailed obstacle planning is the most accuratemethod of determing resource requirements. ARTILLERY DELIVERED SCATTERABLE MINES (ADAM/RAAMS) GROUND EMPLACED MINE SCATTERING SYSTEM (GEMSS) (M128) MODULAR PACK MINE SYSTEM (MOPMS) HELICOPTER DELIVERED AT MINE DISPENSING SYSTEM (M56) USAF DELIVERED SCATTERABLE MINES (GATOR) AT MINE DISPENSING SYSTEM (M57) CONVENTIONAL MINEFIELDS (HAND LAID) DELIBERATE ROAD CRATER HASTY ROAD CRATER CRATERING DEVICE (M180) WITH MINES WIRE OBSTACLES ABATIS ARTILLERY DELIVERED SCATTERABLE MINES (ADAM/RAAMS) (designator MFA) GROUND EMPLACED MINESCATTERING SYSTEM (GEMSS) (M128)

Training Circular (TC)

TC 6-20-5 Field Artillery Delivered Scatterable Mines

PROJECTED PUBLICATIONS

Projected publications are sources of additional information that are scheduled forprinting but not yet available.

Field Manual (FM)

FM 5-101 MobilityFM 5-103 SurvivabilityFM 100-16 Support Operations: Echelons Above CorpsNOTE: These are publications that are scheduled for printing. Upon print, they will bedistributed automatically by a pinpoint distribution and will not be available forrequisition from USA-AG Publications Center, Baltimore, MD, until indexed in DA Pam310-1.